Geometrical product specifications (GPS) - Dimensional measuring equipment - Part 1: Plain limit gauges of linear size (ISO 1938-1:2015)

ISO 1938-1:2015 specifies the most important metrological and design characteristics of plain limit gauges of linear size.
ISO 1938-1:2015 defines the different types of plain limit gauges used to verify linear dimensional specifications associated with linear size.
ISO 1938-1:2015 also defines the design characteristics and the metrological characteristics for these limit gauges as well as the new or wear limits state Maximum Permissible Limits (MPLs) for the new state or wear limits state for these metrological characteristics.
In addition, ISO 1938-1:2015 describes the use of limit gauges. It covers linear sizes up to 500 mm.

Geometrische Produktspezifikation (GPS) - Längenprüftechnik - Teil 1: Grenzlehren und Lehrung der Längenmaße (ISO 1938-1:2015)

Diese Internationale Norm legt die wichtigsten messtechnischen Merkmale und Konstruktionsmerkmale für
glatte Grenzlehren der linearen Größenmaße fest.
Diese Internationale Norm definiert die verschiedenen Arten von glatten Grenzlehren, die für den Nachweis
der Übereinstimmung mit Maßspezifikationen für lineare Größenmaße angewendet werden.
Diese Internationale Norm legt ebenfalls die Konstruktionsmerkmale und messtechnischen Merkmale für
diese Grenzlehren sowie die Grenzwerte für Messabweichungen (MPEs) für Lehren im Neuzustand oder
Verschleißzustand für diese Merkmale fest.
Diese Internationale Norm beschreibt weiterhin die Anwendung von Grenzlehren und deckt lineare
Größenmaße bis zu 500 mm ab.

Spécification géométrique des produits (GPS) - Équipement de mesure dimensionnel - Partie 1: Calibres lisses à limite de taille linéaire (ISO 1938-1:2015)

ISO 1938-1:2015 spécifie les caractéristiques métrologiques et de conception les plus importantes des calibres lisses à limites de taille linéaire.
ISO 1938-1:2015 définit les différents types de calibres lisses à limites utilisés pour vérifier les spécifications dimensionnelles linéaires associées à la taille linéaire.
ISO 1938-1:2015 définit également les caractéristiques de conception et les caractéristiques métrologiques de ces calibres à limites, ainsi que l'état neuf ou l'état limite d'usure des limites maximales tolérées (Maximum Permissible Limits, MPL) de l'état neuf ou de l'état limite d'usure de ces caractéristiques métrologiques.
ISO 1938-1:2015 décrit également l'utilisation des calibres à limites. Elle couvre les tailles linéaires jusqu'à 500 mm.

Specifikacija geometrijskih veličin izdelka (GPS) - Oprema za merjenje dimenzij - 1. del: Ploščati mejni merilniki linearne velikosti (ISO 1938-1:2015)

Ta mednarodni standard določa najpomembnejše meroslovne in oblikovne značilnosti ploščatih mejnih merilnikov linearne velikosti. Ta mednarodni standard določa različne vrste ploščatih mejnih merilnikov, ki se uporabljajo za dokazovanje skladnosti z linearno specifikacijo mer, povezano z linearno velikostjo.
Ta mednarodni standard določa tudi oblikovne in meroslovne značilnosti teh mejnih merilnikov ter MPE pri novem ali izrabljenem stanju za te značilnosti.
Ta mednarodni standard opisuje tudi uporabo mejnih merilnikov in pokriva linearne velikosti do 500 mm.

General Information

Status
Published
Publication Date
17-Nov-2015
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
18-Nov-2015
Completion Date
18-Nov-2015

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Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 1938-1:2016
01-februar-2016

6SHFLILNDFLMDJHRPHWULMVNLKYHOLþLQL]GHOND *36 2SUHPD]DPHUMHQMHGLPHQ]LM

GHO3ORãþDWLPHMQLPHULOQLNLOLQHDUQHYHOLNRVWL ,62

Geometrical product specifications (GPS) - Dimensional measuring equipment - Part 1:

Plain limit gauges of linear size (ISO 1938-1:2015)

Geometrische Produktspezifikation (GPS) - Maßtolerierung - Teil 1: Grenzlehren und

Lehrung der Längenmaße (ISO 1938-1:2015)

Spécification géométrique des produits (GPS) - Équipement de mesure dimensionnel -

Partie 1: Calibres lisses à limite de taille linéaire (ISO 1938-1:2015)
Ta slovenski standard je istoveten z: EN ISO 1938-1:2015
ICS:
17.040.30 Merila Measuring instruments
17.040.40 6SHFLILNDFLMDJHRPHWULMVNLK Geometrical Product
YHOLþLQL]GHOND *36 Specification (GPS)
SIST EN ISO 1938-1:2016 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 1938-1:2016
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SIST EN ISO 1938-1:2016
EN ISO 1938-1
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2015
EUROPÄISCHE NORM
ICS 17.040.10
English Version
Geometrical product specifications (GPS) - Dimensional
measuring equipment - Part 1: Plain limit gauges of linear
size (ISO 1938-1:2015)

Spécification géométrique des produits (GPS) - Geometrische Produktspezifikation (GPS) -

Équipement de mesure dimensionnel - Partie 1: Maßtolerierung - Teil 1: Grenzlehren und Lehrung der

Calibres lisses à limite de taille linéaire (ISO 1938- Längenmaße (ISO 1938-1:2015)

1:2015)
This European Standard was approved by CEN on 27 April 2015.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 1938-1:2015 E

worldwide for CEN national Members.
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SIST EN ISO 1938-1:2016
EN ISO 1938-1:2015 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 1938-1:2016
EN ISO 1938-1:2015 (E)
European foreword

This document (EN ISO 1938-1:2015) has been prepared by Technical Committee ISO/TC 213

"Dimensional and geometrical product specifications and verification" in collaboration with Technical

Committee CEN/TC 290 “Dimensional and geometrical product specification and verification” the

secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by May 2016, and conflicting national standards shall be

withdrawn at the latest by May 2016.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent

rights.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
Endorsement notice

The text of ISO 1938-1:2015 has been approved by CEN as EN ISO 1938-1:2015 without any

modification.
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SIST EN ISO 1938-1:2016
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SIST EN ISO 1938-1:2016
INTERNATIONAL ISO
STANDARD 1938-1
First edition
2015-11-01
Geometrical product specifications
(GPS) — Dimensional measuring
equipment —
Part 1:
Plain limit gauges of linear size
Spécification géométrique des produits (GPS) — Équipement de
mesure dimensionnel —
Partie 1: Calibres lisses à limite de taille linéaire
Reference number
ISO 1938-1:2015(E)
ISO 2015
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

3.1 Limits ............................................................................................................................................................................................................... 2

3.2 Gauge types ................................................................................................................................................................................................ 3

3.3 Characteristics and function of gauges .............................................................................................................................. 6

4 Abbreviated terms and symbols .......................................................................................................................................................... 7

5 Design characteristics for gauges ....................................................................................................................................................... 8

6 Metrological characteristics .................................................................................................................................................................10

6.1 General ........................................................................................................................................................................................................10

6.2 Metrological characteristic relative to the type of limit gauge (GO gauge or

NO GO gauge) ........................................................................................................................................................................................10

7 Maximum permissible limits on metrological characteristics ..........................................................................14

7.1 General ........................................................................................................................................................................................................14

7.2 Limit gauges for internal features of size ......................................................................................................................15

7.3 Limit gauges for external features of size .....................................................................................................................16

7.4 Values for calculation of MPL of limit gauges ............................................................................................................18

8 Proving conformance with specification for limit gauges ....................................................................................21

9 Verification of dimensional specification of a workpiece with limit gauges ......................................21

10 Marking .......................................................................................................................................................................................................................23

Annex A (informative) General principles and application of limit gauging ...........................................................24

Annex B (informative) Description of the specific use of the various gauge types and the

associated uncertainty ................................................................................................................................................................................26

Annex C (informative) Relation to the GPS matrix model ............................................................................................................28

Bibliography .............................................................................................................................................................................................................................30

© ISO 2015 – All rights reserved iii
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical

Barriers to Trade (TBT), see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 213, Geometrical product specifications and

verification.

This first edition cancels and replaces ISO/R 1938:1971, which has been technically revised.

ISO 1938 consists of the following parts, under the general title Geometrical product specifications

(GPS) — Dimensional measuring equipment:
— Part 1: Plain limit gauges of linear size
— Part 2: Reference disk gauges

This part of ISO 1938 does not include requirements for setting plug gauges and setting ring gauges,

which were dealt with in ISO/R 1938:1971, 3.9.4.
This part of ISO 1938 covers the concepts and principles developed in ISO 14978.
iv © ISO 2015 – All rights reserved
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Introduction

This part of ISO 1938 is a geometrical product specification (GPS) standard and is to be regarded as a

general GPS standard (see ISO 14638). It influences chain links E, F and G of the size chain of standards

in the general GPS matrix. For more detailed information of the relation of this part of ISO 1938 to other

standards and the GPS matrix model, see Annex C.

The ISO/GPS matrix model given in ISO 14638 gives an overview of the ISO/GPS system of which this

document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and

the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this

document, unless otherwise indicated.

The terms and concepts used in this first edition of ISO 1938-1 (compared to the former edition

ISO/R 1938:1971) have been changed according to needs and terminology in the other GPS standards.

This part of ISO 1938 deals with verification, using plain limit gauges, of linear sizes for features of size

when the dimensional specifications are required (see ISO 14405-1), for rigid workpieces.

NOTE Tables 4 and 5 use the modifiers given in ISO 14405-1 and ISO 1101.
© ISO 2015 – All rights reserved v
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SIST EN ISO 1938-1:2016
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SIST EN ISO 1938-1:2016
INTERNATIONAL STANDARD ISO 1938-1:2015(E)
Geometrical product specifications (GPS) — Dimensional
measuring equipment —
Part 1:
Plain limit gauges of linear size
1 Scope

This part of ISO 1938 specifies the most important metrological and design characteristics of plain

limit gauges of linear size.

This part of ISO 1938 defines the different types of plain limit gauges used to verify linear dimensional

specifications associated with linear size.

This part of ISO 1938 also defines the design characteristics and the metrological characteristics for

these limit gauges as well as the new or wear limits state Maximum Permissible Limits (MPLs) for the

new state or wear limits state for these metrological characteristics.

In addition, this part of ISO 1938 describes the use of limit gauges. It covers linear sizes up to 500 mm.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 286-1:2010, Geometrical product specifications (GPS) — ISO code system for tolerances on linear

sizes — Part 1: Basis of tolerances, deviations and fits

ISO 1101:2012, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,

orientation, location and run-out

ISO 14405-1:2010, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear

sizes

ISO 14253-1:2013, Geometrical product specifications (GPS) — Inspection by measurement of workpieces

and measuring equipment — Part 1: Decision rules for proving conformity or nonconformity with

specifications

ISO 14253-2:2011, Geometrical product specifications (GPS) — Inspection by measurement of workpieces

and measuring equipment — Part 2: Guidance for the estimation of uncertainty in GPS measurement, in

calibration of measuring equipment and in product verification

ISO 17450-1:2011, Geometrical product specifications (GPS) — General concepts — Part 1: Model for

geometrical specification and verification

ISO 17450-2:2012, Geometrical product specifications (GPS) — General concepts — Part 2: Basic tenets,

specifications, operators, uncertainties and ambiguities

ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

measurement (GUM:1995)

ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated

terms (VIM)
© ISO 2015 – All rights reserved 1
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
3 Terms and definitions

For the purpose of this document, the terms and definitions given in ISO 286-1, ISO 14405-1, ISO 17450-2,

ISO/IEC Guide 98-3 and ISO/IEC Guide 99 and the following definitions apply.
3.1 Limits
3.1.1
maximum material limit of size
MMLS
limit of size corresponding to the maximum material condition of feature of size

Note 1 to entry: MMLS includes the numerical value for the size and the specified association criteria.

Note 2 to entry: A number of different association criteria for size are given in ISO 14660-2 and ISO 14405-1.

3.1.2
least material limit of size
LMLS
limit of size corresponding to the least material condition of feature of size

Note 1 to entry: LMLS includes the numerical value for the size and the specified association criteria.

Note 2 to entry: A number of different association criteria for size are given in ISO 14660-2 and ISO 14405-1.

3.1.3
upper limit of size
ULS
largest permissible size of a feature of size
Note 1 to entry: ULS is a numerical value.
[SOURCE: ISO 286-1:2010, 3.2.3.1]
3.1.4
lower limit of size
LLS
smallest permissible size of a feature of size
Note 1 to entry: LLS is a numerical value.
[SOURCE: ISO 286-1:2010, 3.2.3.2]
3.1.5
upper specification limit
USL

limit of a specification for a metrological characteristic of a gauge having the largest value

3.1.6
lower specification limit
LSL

limit of a specification for a metrological characteristic of a gauge having the smallest value

2 © ISO 2015 – All rights reserved
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
3.2 Gauge types
3.2.1
limit gauge

gauge designed and intended to verify only if workpiece characteristics are inside or outside the

tolerance at one of its tolerance limits

Note 1 to entry: When a limit gauge is designed to verify an internal feature of size (a hole for example), then it

can be called internal limit gauge.

Note 2 to entry: When a limit gauge is designed to verify an external feature of size (a shaft for example), then it

can be called external limit gauge.
Note 3 to entry: General application of limit gauge is given in Annex A.
Note 4 to entry: A limit gauge may be physical or virtual.
3.2.2
plain limit gauge

physical limit gauge with only one or two gauge elements, each one simulating a perfect feature of size,

whose size is derived from upper or lower specification limits of the size of a feature of size

Note 1 to entry: When a plain limit gauge consists of only one element, it is qualified as simple (simple plain limit

gauge: GO plain limit gauge or NO GO plain limit gauge).

Note 2 to entry: When a plain limit gauge consists of two elements, it is qualified as double (double plain limit

gauge: GO and NO GO).
3.2.3
full form cylindrical plug gauge
gauge type A

plain limit gauge designed to simulate a cylinder as a contacting feature with an internal cylinder

Note 1 to entry: See Table 1.

Note 2 to entry: The GO gauge type A simulates a dimensional specification defining the maximum material limit

of size with the envelope requirement when the gauge length is greater or at least equal to the length of the

feature of size of the workpiece.
3.2.4
segmental cylindrical bar gauge
gauge type B

plain limit gauge designed to simulate two opposite angular portions of a cylinder as a contacting

feature with an internal cylinder
Note 1 to entry: See Table 1.
3.2.5
segmental cylindrical bar gauge with reduced gauging surfaces
gauge type C

segmental cylindrical bar gauge designed to simulate two reduced opposite angular portions of a

cylinder as a contacting surface with an internal cylinder
Note 1 to entry: See Table 1.
3.2.6
full form spherical plug gauge
gauge type D

plain limit gauge designed to simulate a circle as a contacting feature with an internal cylinder

Note 1 to entry: See Table 1.
© ISO 2015 – All rights reserved 3
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)

Note 2 to entry: The shape of this gauge type is not spherical, but a torus - per tradition the name is “spherical

plug gauge”.
3.2.7
segmental spherical plug gauge
gauge type E

plain limit gauge designed to simulate two opposite angular portions of a circle as a contacting feature

with an internal cylinder
Note 1 to entry: See Table 1.

Note 2 to entry: The shape of this gauge type is not spherical but a torus - per tradition the name is “segmental

spherical plug gauge”.
3.2.8
bar gauge
gauge type F
full form bar gauge

plain limit gauge designed to simulate two opposite planes as a contacting feature with an internal

feature of size consisting of two opposite planes
Note 1 to entry: See Table 1.
3.2.9
rod gauge with spherical ends
gauge type G

plain limit gauge designed to simulate two opposite points as a contacting feature with an internal

feature of size consisting of two opposite planes or of a cylinder
Note 1 to entry: See Table 1.

Note 2 to entry: The active part of a rod gauge with spherical ends consists only of two points: the two points at

the largest distance between the two spheres.
Table 1 — Types of limit gauge for internal feature of size
Nominal con-
Nominal con-
tacting feature
tacting feature
with feature of
Limit gauge Type Illustration with feature
size of type “two
of size of “type
opposite paral-
Cylinder”
lel planes”
Two opposite par-
Full form cylindrical plug gauge Gauge type A Cylinder
allel straight lines
Two opposite
Two opposite par-
Segmental cylindrical bar gauge Gauge type B angular portions
allel straight lines
of cylinder
Two opposite
Segmental cylindrical bar gauge with angular reduced Two opposite par-
Gauge type C
reduced gauging surfaces portions of cyl- allel line segments
inder
4 © ISO 2015 – All rights reserved
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Table 1 (continued)
Nominal con-
Nominal con-
tacting feature
tacting feature
with feature of
Limit gauge Type Illustration with feature
size of type “two
of size of “type
opposite paral-
Cylinder”
lel planes”
Full form spherical plug gauge Gauge type D Circle Two points
Two opposite
Segmental spherical plug gauge Gauge type E angular portions Two points
of circle
Two opposite par-
Bar gauge Gauge type F Not applicable
allel planes
Rod gauge with spherical ends Gauge type G Two points Two points
3.2.10
full form cylindrical ring gauge
gauge type H

plain limit gauge designed to simulate a cylinder as contacting feature with an external cylinder

Note 1 to entry: See Table 2.
3.2.11
full form notch gauge
gauge type J

plain limit gauge designed to simulate straight lines or flat surfaces on two opposite parallel planes as

contacting features with an external feature of size consisting of a cylinder or two opposite planes

Note 1 to entry: See Table 2.
3.2.12
gap gauge
gauge type K

plain limit gauge designed to simulate portions (straight lines or flat surfaces) on two opposite planes

as contacting feature with an external feature of size consisting of a cylinder or two opposite planes

Note 1 to entry: See Table 2.
© ISO 2015 – All rights reserved 5
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Table 2 — Types of limit gauge for external feature of size
Nominal contacting feature with fea-
ture of size of type:
Limit gauge Type Illustration
“two opposite parallel
“cylinder”
planes”
Full form cylindrical ring gauge Gauge type H Cylinder Not applicable
Two oppo-
site parallel Two opposite parallel
Full form notch gauge Gauge type J
straight planes
lines
Two oppo-
site parallel Two opposite parallel por-
Gap gauge Gauge type K
straight line tions of planes
segments
3.3 Characteristics and function of gauges
3.3.1
non-adjustable gauge

gauge with an inherent, stable and not changeable nominal metrological characteristic

Note 1 to entry: The metrological characteristics of a non-adjustable gauge may change with e.g. temperature

and wear.

EXAMPLE A full form cylindrical plug gauge and a full form cylindrical ring gauge are non-adjustable gauges.

3.3.2
adjustable gauge

gauge designed in a way that the inherent nominal metrological characteristic can be intentionally

changed by the user

Note 1 to entry: The metrological characteristics of an adjustable gauge may also change with e.g.

temperature and wear.

EXAMPLE A variable gap gauge and a variable rod gauge with spherical ends are adjustable gauges.

3.3.3
GO gauge

gauge designed to verify the size of the workpiece relative to maximum material size according to

dimensional specification

Note 1 to entry: Usually relative to the maximum material limit of size (MMLS) of the dimensional specification,

the GO gauge passing over the actual feature of size of the workpiece, defines an acceptance and the GO gauge,

not passing over the actual feature of size of the workpiece defines a non-acceptance.

3.3.4
NO GO gauge

gauge designed to verify the size of the workpiece relative to least material size according to dimensional

specification

Note 1 to entry: Usually relative to the least material limit of size (LMLS) of the dimensional specification, the

NO GO gauge not passing over the actual feature of size of the workpiece defines an acceptance and the NO GO

gauge passing over the actual feature of size of the workpiece defines a non-acceptance.

6 © ISO 2015 – All rights reserved
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
3.3.5
length of gauge element

active length of a gauge in the direction perpendicular to a cross section of the gauged feature of size

Note 1 to entry: For a cylindrical gauge element, it is the length of the cylinder (see Table 4). For a gauge element

of type “two parallel opposite surfaces”, it is the length of the bar or notch (see Table 4). For a gap gauge, it is the

width of the anvils (see Table 4).
3.3.6
height of gauge element

active height of a gauge in the direction parallel to a cross section of the gauged feature of size

Note 1 to entry: For a gauge element of type two parallel opposite surfaces, it is the height of the bar or notch (see

Table 4). For a gap gauge, it is the height of the anvils (see Table 4).
3.3.7
new state specification

specification for metrological characteristics of a new gauge to be used by a

manufacturer or supplier
3.3.8
wear limits state specification

specification for metrological characteristics of a used gauge

Note 1 to entry: The user may use standardized wear limits state specifications, e.g. as given in this part of ISO 1938.

Note 2 to entry: The wear limits state specifications consider the gauge as used, and can include wear limits.

3.3.9
new state permissible limits of a metrological characteristic
permissible limits of a metrological characteristic in a new state specification
3.3.10
wear limits state permissible limits of a metrological characteristic

permissible limits of a metrological characteristic in a wear limits state specification

4 Abbreviated terms and symbols

For the purpose of this document, the abbreviated terms and symbols given in Table 3 apply.

© ISO 2015 – All rights reserved 7
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SIST EN ISO 1938-1:2016
ISO 1938-1:2015(E)
Table 3 — Abbreviated terms and symbols
Description
Abbreviated term
B width of segmental gauge element
F tolerance value of form specification on limit gauge
GO go gauge

H interval tolerance on the size characteristic, S, for a limit gauge in the new state

LT length of
...

SLOVENSKI STANDARD
kSIST FprEN ISO 1938-1:2014
01-januar-2014
[Not translated]

Geometrical product specifications (GPS) - Dimensional measuring equipment - Part 1:

Plain limit gauges of linear size (ISO/FDIS 1938-1:2013)

Geometrische Produktspezifikation (GPS) - Maßtolerierung - Teil 1: Grenzlehren und

Lehrung der Längenmaße (ISO/FDIS 1938-1:2013)

Spécification géométrique des produits (GPS) - Équipement de mesure dimensionnel -

Partie 1: Calibres lisses à limite de taille linéaire (ISO/FDIS 1938-1:2013)
Ta slovenski standard je istoveten z: FprEN ISO 1938-1
ICS:
17.040.10 Tolerance in ujemi Limits and fits
17.040.30 Merila Measuring instruments
kSIST FprEN ISO 1938-1:2014 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST FprEN ISO 1938-1:2014
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kSIST FprEN ISO 1938-1:2014
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 1938-1
ISO/TC 213
Geometrical product specifications
Secretariat: DS
(GPS) - Dimensional measuring
Voting begins on:
2013-11-14 equipment —
Voting terminates on:
Part 1:
2014-01-14
Plain limit gauges of linear size
Spécification géométrique des produits (GPS) — Équipement de
mesurage dimensionnel —
Partie 1: Calibres lisses à limite de taille linéaire
Please see the administrative notes on page iii
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 1938-1:2013(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO 2013
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2013

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
ISO/CEN PARALLEL PROCESSING

This final draft has been developed within the International Organization for Standardization (ISO), and pro-

cessed under the ISO-lead mode of collaboration as defined in the Vienna Agreement. The final draft was

established on the basis of comments received during a parallel enquiry on the draft.

This final draft is hereby submitted to the ISO member bodies and to the CEN member bodies for a parallel

two-month approval vote in ISO and formal vote in CEN.
Positive votes shall not be accompanied by comments.
Negative votes shall be accompanied by the relevant technical reasons.
© ISO 2013 – All rights reserved iii
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

3.1 Limits ............................................................................................................................................................................................................... 2

3.2 Gauge types ................................................................................................................................................................................................ 3

3.3 Characteristics and function of gauges .............................................................................................................................. 6

4 Abbreviated terms and symbols .......................................................................................................................................................... 7

5 Design characteristics for gauges ....................................................................................................................................................... 8

6 Metrological characteristics .................................................................................................................................................................10

6.1 General ........................................................................................................................................................................................................10

6.2 Metrological characteristic relative to the type of limit gauge (GO gauge or

NO GO gauge) ........................................................................................................................................................................................10

7 Maximum permissible limits on metrological characteristics ..........................................................................15

7.1 General .......................................................................................................................................................................................................15

7.2 Limit gauges for internal features of size ......................................................................................................................15

7.3 Limit gauges for external features of size .....................................................................................................................17

7.4 Values for calculation of MPL of limit gauges ...........................................................................................................18

8 Proving conformance with specification for limit gauges ....................................................................................22

9 Verification of dimensional specification of a workpiece with limit gauges ......................................22

10 Marking .......................................................................................................................................................................................................................24

Annex A (informative) General principles and application of limit gauging ...........................................................25

Annex B (informative) Description of the specific use of the various gauge types and the

associated uncertainty ................................................................................................................................................................................27

Annex C (informative) Relation to the GPS matrix model ............................................................................................................29

Bibliography .............................................................................................................................................................................................................................31

iv © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers

to Trade (TBT), see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 213, Geometrical product specifications and

verification.

This first edition cancels and replaces ISO/R 1938:1971, which has been technically revised.

ISO 1938 consists of the following parts, under the general title Geometrical product specifications

(GPS) — Dimensional measuring equipment:
— Part 1: Plain limit gauges of linear size

This part of ISO 1938 does not include requirements for setting plug gauges and setting ring gauges,

which were dealt with in ISO/R 1938:1971, 3.9.4.
This part of ISO 1938 covers the concepts and principles developed in ISO 14978.
© ISO 2013 – All rights reserved v
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Introduction

This part of ISO 1938 is a geometrical product specification (GPS) standard and is to be regarded as a

general GPS standard (see ISO/TR 14638). It influences chain links 4, 5 and 6 of the size chain of standards

in the general GPS matrix. For more detailed information of the relation of this part of ISO 1938 to other

standards and the GPS matrix model, see Annex C.

The ISO/GPS Masterplan given in ISO/TR 14638 gives an overview of the ISO/GPS system of which this

document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and

the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this

document, unless otherwise indicated.

The terms and concepts used in this first edition of ISO 1938-1 (compared to the former edition

ISO/R 1938:1971) have been changed according to needs and terminology in the other GPS standards.

This part of ISO 1938 deals with verification, using plain limit gauges, of linear sizes for features of size

when the dimensional specifications are required (see ISO 14405-1), for rigid workpieces.

NOTE Tables 4 and 5 use the modifiers given in ISO 14405-1 and ISO 1101.
vi © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 1938-1:2013(E)
Geometrical product specifications (GPS) - Dimensional
measuring equipment —
Part 1:
Plain limit gauges of linear size
1 Scope

This part of ISO 1938 specifies the most important metrological and design characteristics of plain limit

gauges of linear size.

This part of ISO 1938 defines the different types of plain limit gauges used to verify linear dimensional

specifications associated with linear size.

This part of ISO 1938 also defines the design characteristics and the metrological characteristics for

these limit gauges as well as the new or wear limits state Maximum Permissible Limits (MPLs) for the

new state or wear limits state for these metrological characteristics.

In addition, this part of ISO 1938 describes the use of limit gauges. It covers linear sizes up to 500 mm.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 286-1:2010, Geometrical product specifications (GPS) — ISO code system for tolerances on linear

sizes — Part 1: Basis of tolerances, deviations and fits

ISO 1101:2012, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,

orientation, location and run-out

ISO 14405-1:2010, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear sizes

ISO 14253-1:2013, Geometrical product specifications (GPS) — Inspection by measurement of workpieces and

measuring equipment — Part 1: Decision rules for proving conformity or nonconformity with specifications

ISO 14253-2:2011, Geometrical product specifications (GPS) — Inspection by measurement of workpieces

and measuring equipment — Part 2: Guidance for the estimation of uncertainty in GPS measurement, in

calibration of measuring equipment and in product verification

ISO 17450-1:2011, Geometrical product specifications (GPS) — General concepts — Part 1: Model for

geometrical specification and verification

ISO 17450-2:2012, Geometrical product specifications (GPS) — General concepts — Part 2: Basic tenets,

specifications, operators, uncertainties and ambiguities

ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

measurement (GUM:1995)

ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated

terms (VIM)
© ISO 2013 – All rights reserved 1
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
3 Terms and definitions

For the purpose of this document, the terms and definitions given in ISO 286-1, ISO 14405-1, ISO 17450-2,

ISO/IEC Guide 98-3 and ISO/IEC Guide 99 and the following definitions apply.
3.1 Limits
3.1.1
maximum material limit of size
MMLS
limit of size corresponding to the maximum material condition of feature of size

Note 1 to entry: MMLS includes the numerical value for the size and the specified association criteria.

Note 2 to entry: A number of different association criteria for size are given in ISO 14660-2 and ISO 14405-1.

3.1.2
least material limit of size
LMLS
limit of size corresponding to the least material condition of feature of size

Note 1 to entry: LMLS includes the numerical value for the size and the specified association criteria.

Note 2 to entry: A number of different association criteria for size are given in ISO 14660-2 and ISO 14405-1.

3.1.3
upper limit of size
ULS
largest permissible size of a feature of size
Note 1 to entry: ULS is a numerical value.
[SOURCE: ISO 286-1:2010, 3.2.3.1]
3.1.4
lower limit of size
LLS
smallest permissible size of a feature of size
Note 1 to entry: LLS is a numerical value.
[SOURCE: ISO 286-1:2010, 3.2.3.2]
3.1.5
upper specification limit
USL

limit of a specification for a metrological characteristic of a gauge having the largest value

3.1.6
lower specification limit
LSL

limit of a specification for a metrological characteristic of a gauge having the smallest value

2 © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
3.2 Gauge types
3.2.1
limit gauge

gauge designed and intended to verify only if workpiece characteristics are inside or outside the

tolerance at one of its tolerance limits

Note 1 to entry: When a limit gauge is designed to verify an internal feature of size (an hole for example), then it

can be called internal limit gauge.

Note 2 to entry: When a limit gauge is designed to verify an external feature of size (a shaft for example), then it

can be called external limit gauge.
Note 3 to entry: General application of limit gauge is given in Annex A.
Note 4 to entry: A limit gauge may be physical or virtual.
3.2.2
plain limit gauge

physical limit gauge with only one or two gauge elements, each one simulating a perfect feature of size,

whose the size is derived from upper or lower specification limits of the size of a feature of size

Note 1 to entry: When a plain limit gauge consists of only one element, it is qualified as simple (simple plain limit

gauge: GO plain limit gauge or NO GO plain limit gauge).

Note 2 to entry: When a plain limit gauge consists of two elements, it is qualified as double (double plain limit

gauge: GO and NO GO).
3.2.3
full form cylindrical plug gauge
gauge type A

plain limit gauge designed to simulate a cylinder as a contacting feature with an internal cylinder

Note 1 to entry: See Table 1.

Note 2 to entry: The GO gauge type A simulates a dimensional specification defining the maximum material limit

of size with the envelope requirement when the gauge length is greater or at least equal to the length of the

feature of size of the workpiece.
3.2.4
segmental cylindrical bar gauge
gauge type B

plain limit gauge designed to simulate two opposite angular portions of a cylinder as a contacting feature

with a internal cylinder
Note 1 to entry: See Table 1.
3.2.5
segmental cylindrical bar gauge with reduced gauging surfaces
gauge type C

segmental cylindrical bar gauge designed to simulate two reduced opposite angular portions of a

cylinder as a contacting surface with an internal cylinder
Note 1 to entry: See Table 1.
3.2.6
full form spherical plug gauge
gauge type D
disc gauge

plain limit gauge designed to simulate a circle as a contacting feature with an internal cylinder

Note 1 to entry: See Table 1.
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)

Note 2 to entry: The shape of this gauge type is not spherical, but a torus - per tradition the name is “spherical

plug gauge”.
3.2.7
segmental spherical plug gauge
gauge type E

plain limit gauge designed to simulate two opposite angular portions of a circle as a contacting feature

with an internal cylinder
Note 1 to entry: See Table 1.

Note 2 to entry: The shape of this gauge type is not spherical but a torus - per tradition the name is “segmental

spherical plug gauge”.
3.2.8
bar gauge
gauge type F
full form bar gauge

plain limit gauge designed to simulate two opposite planes as a contacting feature with an internal

feature of size consisting of two opposite planes
Note 1 to entry: See Table 1.
3.2.9
rod gauge with spherical ends
gauge type G

plain limit gauge designed to simulate two opposite points as a contacting feature with a internal feature

of size consisting of two opposite planes or of a cylinder
Note 1 to entry: See Table 1.

Note 2 to entry: The active part of a rod gauge with spherical ends consists only of two points: the two points at

the largest distance between the two spheres.
Table 1 — Types of limit gauge for internal feature of size
Nominal con-
Nominal con-
tacting feature
tacting feature
with feature of
Limit gauge Type Illustration with feature
size of type “two
of size of “type
opposite paral-
Cylinder”
lel planes”
Two opposite
Full form cylindrical plug gauge Gauge type A Cylinder parallel straight
lines
Two opposite Two opposite
Segmental cylindrical bar gauge Gauge type B angular por- parallel straight
tions of cylinder lines
Two opposite
Two opposite
Segmental cylindrical bar gauge angular reduced
Gauge type C parallel line seg-
with reduced gauging surfaces portions of
ments
cylinder
4 © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Table 1 (continued)
Nominal con-
Nominal con-
tacting feature
tacting feature
with feature of
Limit gauge Type Illustration with feature
size of type “two
of size of “type
opposite paral-
Cylinder”
lel planes”
Full form spherical plug gauge Gauge type D Circle Two points
Two opposite
Segmental spherical plug gauge Gauge type E angular por- Two points
tions of circle
Two opposite
Bar gauge Gauge type F Not applicable
parallel planes
Rod gauge with spherical ends Gauge type G Two points Two points
3.2.10
full form cylindrical ring gauge
gauge type H

plain limit gauge designed to simulate a cylinder as contacting feature with an external cylinder

Note 1 to entry: See Table 2.
3.2.11
full form notch gauge
gauge type J

plain limit gauge designed to simulate straight lines or flat surfaces on two opposite parallel planes as

contacting features with an external feature of size consisting of a cylinder or two opposite planes

Note 1 to entry: See Table 2.
3.2.12
gap gauge
gauge type K

plain limit gauge designed to simulate portions (straight lines or flat surfaces) on two opposite planes as

contacting feature with an external feature of size consisting of a cylinder or two opposite planes

Note 1 to entry: See Table 2.
© ISO 2013 – All rights reserved 5
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Table 2 — Types of limit gauge for external feature of size
Nominal contacting feature with fea-
ture of size of type:
Limit gauge Type Illustration
“cylinder” “two opposites planes”
Full form cylindrical ring gauge Gauge type H Cylinder Not applicable
Two oppo-
site parallel Two opposite parallel
Full form notch gauge Gauge type J
straight planes
lines
Two oppo-
site parallel Two opposite parallel por-
Gap gauge Gauge type K
straight tions of planes
segments
3.3 Characteristics and function of gauges
3.3.1
non-adjustable gauge

gauge with an inherent, stable and not changeable nominal metrological characteristic

Note 1 to entry: The metrological characteristics of a non-adjustable gauge may change with e.g. temperature and

wear.

EXAMPLE A full form cylindrical plug gauge and a full form cylindrical ring gauge are non-adjustable gauges.

3.3.2
adjustable gauge

gauge designed in a way that the inherent nominal metrological characteristic can be intentionally

changed by the user

Note 1 to entry: The metrological characteristics of a adjustable gauge may also change with e.g. temperature and

wear.

EXAMPLE A variable gap gauge and a variable rod gauge with spherical ends are adjustable gauges.

3.3.3
GO gauge

gauge designed to verify the size of the workpiece relative to maximum material size according to

dimensional specification

Note 1 to entry: Usually relative to the maximum material limit of size (MMLS) of the dimensional specification,

the GO gauge passing over the actual feature of size of the workpiece, defines an acceptance and the GO gauge, not

passing over the actual feature of size of the workpiece defines a non-acceptance.

3.3.4
NO GO gauge

gauge designed to verify the size of the workpiece relative to least material size according to dimensional

specification

Note 1 to entry: Usually relative to the least material limit of size (LMLS) of the dimensional specification, the

NO GO gauge not passing over the actual feature of size of the workpiece defines an acceptance and the NO GO

gauge passing over the actual feature of size of the workpiece defines a non-acceptance.

6 © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
3.3.5
length of gauge element

active length of a gauge in the direction perpendicular to a cross section of the gauged feature of size

Note 1 to entry: For a cylindrical gauge element, it is the length of the cylinder (see Table 4). For a gauge element

of type “two parallel opposite surfaces”, it is the length of the bar or notch (see Table 4). For a gap gauge, it is the

width of the anvils (see Table 4).
3.3.6
height of gauge element

active height of a gauge in the direction parallel to a cross section of the gauged feature of size

Note 1 to entry: For a gauge element of type two parallel opposite surfaces, it is the height of the bar or notch (see

Table 4). For a gap gauge, it is the height of the anvils (see Table 4).
3.3.7
new state specification

specification for metrological characteristics of a new gauge to be used by a

manufacturer or supplier
3.3.8
wear limits state specification

specification for metrological characteristics of a used gauges

Note 1 to entry: The user may use standardized wear limits state specifications, e.g. as given in this part of ISO 1938.

Note 2 to entry: The wear limits state specifications consider the gauge as used, and can include wear limits.

3.3.9
new state permissible limits of a metrological characteristic
permissible limits of a metrological characteristic in a new state specification
3.3.10
wear limits state permissible limits of a metrological characteristic

permissible limits of a metrological characteristic in a wear limits state specification

4 Abbreviated terms and symbols

For the purpose of this document, the abbreviated terms and symbols given in Table 3 apply.

© ISO 2013 – All rights reserved 7
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)
Table 3 — Abbreviated terms and symbols
Description
Abbreviated term
B width of segmental gauge element
F tolerance value of form specification on limit gauge
GO go gauge

H interval tolerance on the size characteristic, S, for a limit gauge in the new state

LT Total length of gauge element
HG height of gauge element
USL upper specification limit (of a gauge)
LG length of gauge element
LSL lower specification limit (of a gauge)
LMLS least material limit of size
M new state gauge
MMLS maximum material limit of size
MPL maximum permissible limits of a metrological characteristic
NO GO no go gauge
S size
SR spherical radius of the gauge
T tolerance
U wear limits state gauge
W workpiece
Symbol

Y amount outside of workpiece tolerance limit taking into account a margin of wear limit

for internal feature of size

amount outside of workpiece tolerance limit taking into account a margin of wear limit

for external feature of size

Z Distance between centre of tolerance for GO new state gauge and the lower specification

limit of an internal feature of size of a workpiece

z Distance between centre of tolerance for GO new state gauge and the upper specification

limit of an external feature of size of a workpiece
α safety allowance for measurement uncertainty for internal feature of size
α safety allowance for measurement uncertainty for external feature of size
5 Design characteristics for gauges

The material used for gauges shall be suitably selected with due consideration to its size stability,

durability and stiffness.

Gauging elements shall normally be manufactured from a high quality steel suitably selected to provide a

high degree of wear resistance after heat treatment. Other wear-resistant materials, e.g. tungsten carbide,

may be used provided that their wear qualities are not less than those of the steel specified above.

NOTE The temperature expansion coefficient of the material used is to be considered together with the

wear resistance.
8 © ISO 2013 – All rights reserved
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kSIST FprEN ISO 1938-1:2014
ISO/FDIS 1938-1:2013(E)

Hard plating or other surface treatments in order to improve the wear resistance of the surface may

also be applied to gauging surfaces, but the thickness of deposit shall at least be of an amount, that an

acceptable gauge always has a fully intact layer of wear resistant material.

The hardness of the gauging surface shall not be less than 670 HV 30 (approximately 58 HRC), irrespective

of the type of material.

There may be specific applications where the use of special materials (e. g. aluminium and glass) is

required by the nature of the workpiece or the manufacturing environment. In such cases it may not be

possible to have the required hardness or wear resistance.

The gauging surface shall be finished by fine grinding or lapping or a process which results in a smooth

type of surface. The surface roughness of gauging surface face shall be specified and the R value shall

not exceed 10 % of the new state gauge MPL for size (see Example and Table 7) with a upper limit va

...

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