Tools for woodworking - Safety requirements - Part 2: Requirements for the shank of shank mounted milling

This European Standard specifies the determination of the maximum speed for given eccentricity at clamping devices for the shank strength of milling tools with cylindrical and taper shank. It also specifies the marking of the tool. Bore mounted tools which are mounted on an arbor shall be considered as a shank mounted tool.

Maschinen-Werkzeuge für Holzbearbeitung - Sicherheitstechnische Anforderungen - Teil 2: Anforderungen für den Schaft von Fräswerkzeugen/Kreissägeblätter

Outils pour le travail du bois - Prescriptions de sécurité - Partie 2 : Prescriptions pour les queues des fraises à queue

Orodja za obdelavo lesa - Varnostne zahteve - 2. del: Zahteve za držalo rezkalnih orodij

Ta evropski standard določa največje hitrosti za dano ekscentričnost pri vpenjalnih napravah za moč stojala frezal s cilindričnim in stožčastim stojalom. Prav tako določa označevanje orodja. Orodja, ki se pritrdijo v izvrtino in so pritrjena na stojalo, naj bi bila obravnavana kot orodja, pritrjena na stojalo.

General Information

Status
Published
Public Enquiry End Date
07-Aug-2016
Publication Date
08-Jan-2018
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
05-Dec-2017
Due Date
09-Feb-2018
Completion Date
09-Jan-2018

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SLOVENSKI STANDARD
SIST EN 847-2:2018
01-februar-2018
1DGRPHãþD
SIST EN 847-2:2014

Orodja za obdelavo lesa - Varnostne zahteve - 2. del: Zahteve za držalo rezkalnih

orodij

Tools for woodworking - Safety requirements - Part 2: Requirements for the shank of

shank mounted milling

Maschinen-Werkzeuge für Holzbearbeitung - Sicherheitstechnische Anforderungen - Teil

2: Anforderungen für den Schaft von Fräswerkzeugen/Kreissägeblätter

Outils pour le travail du bois - Prescriptions de sécurité - Partie 2 : Prescriptions pour les

queues des fraises à queue
Ta slovenski standard je istoveten z: EN 847-2:2017
ICS:
25.100.20 Orodja za frezanje Milling tools
79.120.10 Lesnoobdelovalni stroji Woodworking machines
SIST EN 847-2:2018 en,fr,de

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

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SIST EN 847-2:2018
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SIST EN 847-2:2018
EN 847-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2017
EUROPÄISCHE NORM
ICS 79.120.10 Supersedes EN 847-2:2013
English Version
Tools for woodworking - Safety requirements - Part 2:
Requirements for the shank of shank mounted milling
tools/circular saw blades

Outils pour le travail du bois - Prescriptions de sécurité Maschinen-Werkzeuge für Holzbearbeitung -

- Partie 2 : Prescriptions pour les queues des fraises à Sicherheitstechnische Anforderungen - Teil 2:

queue Anforderungen für den Schaft von
Fräswerkzeugen/Kreissägeblätter
This European Standard was approved by CEN on 21 August 2017.

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, Serbia, 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

© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 847-2:2017 E

worldwide for CEN national Members.
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SIST EN 847-2:2018
EN 847-2:2017 (E)
Contents Page

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

Introduction .................................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 5

4 List of significant hazards ............................................................................................................................ 6

5 Safety requirements ....................................................................................................................................... 6

5.1 General requirements for cylindrical shank ......................................................................................... 6

5.2 Stability of the shank of shank mounted tools ..................................................................................... 7

5.3 Stability of HSK mounted tools ................................................................................................................ 13

6 Marking of tools with cylindrical shank .............................................................................................. 15

Annex A (informative) Examples of calculation ............................................................................................. 17

A.1 Example of calculation of n ............................................................................................................... 17

shank

A.2 Examples of calculations of n .............................................................................................................. 18

HSK

Annex B (normative) Method of measuring the eccentricity at clamping devices ............................ 19

Annex C (informative) Recommended minimum clamping forces ......................................................... 20

Bibliography ................................................................................................................................................................. 21

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SIST EN 847-2:2018
EN 847-2:2017 (E)
European foreword

This document (EN 847-2:2017) has been prepared by Technical Committee CEN/TC 142

“Woodworking machines - Safety”, the secretariat of which is held by UNI.

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 2018, and conflicting national standards shall be

withdrawn at the latest by May 2018.

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

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 847-2:2013.

According to the CEN-CENELEC Internal Regulations, the national standards organisations 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
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SIST EN 847-2:2018
EN 847-2:2017 (E)
Introduction

The content of this European Standard is aimed at eliminating hazards which can lead to overloading of

the shank of shank mounted milling tools for woodworking by excessive rotational speeds.

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SIST EN 847-2:2018
EN 847-2:2017 (E)
1 Scope

This European Standard specifies the determination of the maximum speed for given eccentricity at

clamping devices for the shank strength of milling tools with cylindrical and taper shank. It also

specifies the marking of the tool. Bore mounted tools e.g. milling tools, circular saw blades which are

mounted on an arbor should be considered as a shank mounted tool.

This European Standard complements EN 847-1:2017 and applies also for shank tools with a cutting

diameter of less than 16 mm.

This European Standard is not applicable for shanks of tools according to this scope, which are

manufactured before the date of its publication.
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.

EN 847-1:2017, Tools for woodworking — Safety requirements — Part 1: Milling tools, circular saw

blades

EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk

reduction (ISO 12100:2010)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 847-1:2017 and the following

apply.
3.1
7/24 shank
type of tool holder with a 7/24 cone ratio taper
3.2
hollow taper shank
HSK

type of tool holder with a short hollow taper with high positioning accuracy and high grade of rigidity

that contacts the spindle on two surfaces
3.3
arbor

device to be mounted on the machine spindle interface and which is designed to carry bore type cutting

tools
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SIST EN 847-2:2018
EN 847-2:2017 (E)
4 List of significant hazards
Table 1 shows the list of significant hazards.
Table 1 — List of significant hazards
Hazard according to Condition or causes of Corresponding clause of
hazard related to the tool EN 847–2
EN ISO 12100:2010
Mechanical hazards due to:
Breaking of the tool 5
Inadequacy of mechanical strength
Vibration Dynamic unbalance of tool 5
Variations in the rotational speed of
Breaking of the tool 5
tools
5 Safety requirements
5.1 General requirements for cylindrical shank
The minimum value for the clamping length l shall be as given in Table 2.
e min
Table 2 — Minimum clamping length l
e min
d ≤ 10 mm 10 mm < d < 25 mm d ≥ 25 mm
2 2 2
l = 20 mm l = 2 ⋅ d (mm) l = 1,8 ⋅ d (mm)
e min e min 2 e min 2

The tolerance of the shank diameter d shall be h6 for d ≥ 12 mm and h8 for d < 12 mm.

2 2 2
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SIST EN 847-2:2018
EN 847-2:2017 (E)
5.2 Stability of the shank of shank mounted tools
5.2.1 General

For descriptions of symbols for the stability of the shank of shank mounted tools, see Table 3.

Table 3 — Stability of the shank of shank mounted tools — Symbols and units
Symbol Description Unit
diameter
a) shank diameter d
d mm
b) cone diameter d
c) with axial force: d (calculated); without axial force: d
4 arbor
d maximum diameter of the cutting part mm
cut
shank diameter, see Figure 2 mm
d cone diameter, see Figure 3 mm
calculated hub diameter, see Figure 4 mm
d shank diameter of the arbor, see Figure 4 mm
arbor
− 2
E modulus of elasticity of the shank material N mm
maximum permissible eccentricity at clamping device mm
f form factor —
f safety factor (f = 4) —
s s
axial clamping force, see Figure 4 N
balance quality grade of the tool set (individual tools, arbor, spacers, HSK):
− 1

G product of the permissible eccentricity and the angular velocity according to EN 847– mm s

1:2017
I second moment of area mm
height of cutting part mm
cut
l free shank length mm

l , l , l , ... axial distance of the gravity centre of the mass m , m , m , ... mm

1 2 3 1 2 3
axial distance of gravity centre, see Figure 1 mm
l clamping length mm
total length of shank mm
m , m , m , ... mass of the parts of the tool set, see Figure 1 g
1 2 3
m mass of the cutting part in the area of l , see Figure 2 g
cut cut
m* mass of the tool in the area (l + l ) g
0 cut
m * reduced mass of the cutting part, see Figure 2 g
cut
− 1
n operational speed min
− 1
n maximum permissible rotational speed with regard to shank strength min
shank
S centre of gravity —
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SIST EN 847-2:2018
EN 847-2:2017 (E)
W section modulus mm
− 2
σ fatigue strength under reversed bending stresses of shank material N mm
− 3
ρ density of material (e.g. shank, tool body, spacers) g mm

The maximum permissible rotational speed of shank mounted tools n shall be calculated referring

shank
to the shank strength.
For calculation of n with a given e the following formula applies:
shank sp
 
W ⋅ W ⋅ ⋅ l
σ σ
 
2 w w 6
− G + + ⋅ + ⋅
G e 10
 
3 ⋅ E ⋅ I
 
⋅ l
 
(1)
= ⋅
shank
f ⋅ π
s W ⋅ ⋅
3 ⋅ E ⋅ I
with
I = π⋅ (2)
W π⋅ (3)
For balance quality, see EN 847-1:2017.

Better balance quality grades for tools or tool sets may be applied, if these can be permanently

maintained due to the tool design.
NOTE 1 The safety requirements for th
...

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