ISO/DIS 3408-2

Ball screws

Vis à billes

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 3408-2
ISO/TC 39 Secretariat: SNV
Voting begins on: Voting terminates on:
2020-05-19 2020-08-11
Ball screws —
Part 2:
Nominal diameters and nominal leads — Metric series
Vis à billes —
Partie 2: Diamètres et pas hélicoïdaux, nominaux — Série métrique
ICS: 25.060.99
Member bodies are requested to consult relevant national interests in ISO/TC
4/SC 11 before casting their ballot to the e-Balloting application.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 3408-2:2020(E)
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 SUPPORTING DOCUMENTATION. ISO 2020
---------------------- Page: 1 ----------------------
ISO/DIS 3408-2:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 3408-2:2020(E)
Contents Page

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

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

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

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols .......................................................................................................................................................................................................................... 1

5 Nominal diameters, nominal leads and their combinations .................................................................................. 2

6 Mounting dimensions for ball screw nuts, type B6, B8 and B4, A6 and C6 ..............................................4

Bibliography .............................................................................................................................................................................................................................19

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/DIS 3408-2:2020(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 World Trade Organization (WTO) principles in the

Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.

The committee responsible for this document is ISO/TC 39 and ISO/TC 4, which revised this document

in the Joint Working Group 7 (JWG 7).

This second edition cancels and replaces the first edition of ISO 3408-2:1991, which has been technically

revised.
The changes to the previous version are:
— Substantial review of technical state of the art;

— Definition of three series of ball screws reflecting different international standards;

— Addition of dimensions reflecting current market situations and
— Defining different types of flanges reflecting state of the art.
ISO 3408 consists of the following parts:
Ball screws – Part 1: Vocabulary and designation

Ball screws – Part 2: Nominal diameters, leads, nut dimensions and nominal leads – Metric series

Ball screws – Part 3: Acceptance conditions and acceptance tests
Ball screws – Part 4: Static axial rigidity

Part 5: Ball screws - Part 5: Static and dynamic axial load ratings and operational life

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

iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/DIS 3408-2:2020(E)

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 voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html..
© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
DRAFT INTERNATIONAL STANDARD ISO/DIS 3408-2:2020(E)
Ball screws —
Part 2:
Nominal diameters and nominal leads — Metric series
1 Scope

This document specifies the nominal diameters and nominal leads, mounting dimensions for ball

screw nuts and mounting bolts for metric ball screws. It also gives preferred combinations of nominal

diameter and nominal lead and a general plan which includes the additional combinations to be used

when it becomes necessary to deviate from the preferred combinations.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

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

ISO 3408-1, Ball screws — Part 1: Vocabulary and designation
ISO 4762, Hexagon socket head cap screws
3 Terms and definitions

For the purpose of this document, the terms and definitions given in ISO 3408-1 apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Symbols
Symbol Description Units
α Contact angle degrees, °
γ Geometry factor –
φ Lead angle degrees, °
Dynamic axial load rating for the ball screw shaft per single loaded turnN
d Nominal diameter mm
D Ball screw nut outer diameter mm
D Mounting bolt pitch circle diameter mm
D Flange mounting bolt diameter mm
© ISO 2020 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO/DIS 3408-2:2020(E)
D Flange outer diameter mm
D Screw head counter bore diameter mm
Ball pitch circle diameter mm
Ball diameter mm
F Axial load at the opening limit of the nut flange kN
a max
F Preload N
l Number of loaded turns –
Characteristic of basic static axial load rating –
L Centering diameter length mm
L Collar length mm
L Flange length mm
L Flat flange width mm
L Counter bore depth mm
Lubrication port thread length mm
LL,
h 10
P Nominal lead mm
Q Thread of lubrication port
T Tightening torque of one bolt Nm
5 Nominal diameters, nominal leads and their combinations

Nominal diameters, nominal leads and their combinations are shown in Table 1. Preferred combination

of nominal diameter and lead are highlighted in grey and bold.
2 © ISO 2020 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/DIS 3408-2:2020(E)
© ISO 2020 – All rights reserved 3
Table 1 — Nominal diameters, nominal leads and their combinations
Nominal diam- Nominal lead P [mm]
eter d [mm]
1 1,5 2 2,5 3 4 5 6 8 10 12 15 16 20 25 30 32 40 50
4 1
5 1 1,5
6 1 1,5 2 2,5
8 1 1,5 2 2,5 3 4 5 6 8 10 12
10 1 1,5 2 2,5 3 4 5 6 8 10 12
12 2 2,5 3 4 5 6 8 10 12 15 16 20 25 30
14 2 2,5 3 4 5 6 8 10 12 15 16 20 25 30
16 2 2,5 3 4 5 6 8 10 12 15 16 20 25 30
20 3 4 5 6 8 10 12 15 16 20 25 30 32 40 50
25 4 5 6 8 10 12 15 16 20 25 30 32 40 50
28 4 5 6 8 10 12 15 16 20 25 30 32 40 50
32 4 5 6 8 10 12 15 16 20 25 30 32 40 50
36 4 5 6 8 10 12 15 16 20 25 30 32 40 50
40 5 6 8 10 12 15 16 20 25 30 32 40 50
45 5 6 8 10 12 15 16 20 25 30 32 40 50
50 5 6 8 10 12 15 16 20 25 30 32 40 50
63 5 6 8 10 12 15 16 20 25 30 32 40 50
80 6 8 10 12 15 16 20 25 30 32 40 50
100 10 12 15 16 20 25 30 32 40 50
125 10 12 15 16 20 25 30 32 40 50
160 12 15 16 20 25 30 32 40 50
---------------------- Page: 8 ----------------------
ISO/DIS 3408-2:2020(E)
6 Mounting dimensions for ball screw nuts, type B6, B8 and B4, A6 and C6

There are three series of ball screw nut dimensions standardized. In Table 2, 3 and 4 different types

of ball screw nuts are shown. The following list shows these series of ball screws along with the

corresponding figures and dimension tables.

— Series 1 (internal recirculation): depicted in Figure 1 to 3; dimensions are shown in Table 2;

— Series 2 (internal recirculation): depicted in Figure 3 to 5; dimensions are shown in Table 3;

— Series 3 (external recirculation): depicted in Figure 3 to 5; dimensions are shown in Table 4.

Further design detail alternatives are given in Figure 6.

NOTE The character B in the type description e.g. B4 represents the flange type and is based on the previous

definition, where A represents round type, B two flats and C one flat flange type. The corresponding numbers

represent the number of mounting holes on the flange (e.g. two flats flange type with 4 holes would be B4).

Key

1 If the position of the lubrication port is not sufficient, it can be sealed and replaced by a new axial hole on

either side of the flange. Details need to be defined separately.
L The length of the ball screw nut is manufacturer specific.

L The position of the thread for the lubrication port of the ball screw nut is manufacturer specific.

NOTE See Figure 6 for detail X and all dimensions in Table 2
Figure 1 — Mounting dimensions for ball screw nuts, type B6
4 © ISO 2020 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/DIS 3408-2:2020(E)
Key

1 If the position of the lubrication port is not sufficient, it can be sealed and replaced by a new axial hole on

either side of the flange. Details need to be defined separately.
L The length of the ball screw nut is manufacturer specific.

L The position of the thread for the lubrication port of the ball screw nut is manufacturer specific.

NOTE See Figure 6 for detail X and all dimensions in Table 2
Figure 2 — Mounting dimensions for ball screw nuts, type B8
Key
L The length of the ball screw nut is manufacturer specific.

NOTE See Figure 6 for detail X and all dimensions in Table 2, Table 3 and Table 4

Figure 3 — Mounting dimensions for ball screw nuts, type B4
© ISO 2020 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO/DIS 3408-2:2020(E)
Key

1 If the position of the lubrication port is not sufficient, it can be sealed and replaced by a new axial hole on either

side of the flange. Details need to be defined separately.
L The length of the ball screw nut is manufacturer specific.
L Depth of the lubrication port. This dimension is manufacturer specific.

L The position of the thread for the lubrication port of the ball screw nut is manufacturer specific.

NOTE See Figure 6 for detail X and all dimensions in Table 3 and 4
Figure 4 — Mounting dimensions for ball screw nuts, type A6
6 © ISO 2020 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/DIS 3408-2:2020(E)
Key

1 If the position of the lubrication port is not sufficient, it can be sealed and replaced by a new axial hole on either

side of the flange. Details need to be defined separately.
L The length of the ball screw nut is manufacturer specific.
L Depth of the lubrication port. This dimension is manufacturer specific.

L The position of the thread for the lubrication port of the ball screw nut is manufacturer specific.

NOTE See Figure 4 for detail X and all dimensions in Table 3 and 4
Figure 5 — Mounting dimensions for ball screw nuts, type C6
Detail X
0 ≤ L ≤ L
3 3max
collar without centring collar with centring
Figure 6 — Alternatives for detail X (in Figures 1 through 6)
© ISO 2020 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO/DIS 3408-2:2020(E)
8 © ISO 2020 – All rights reserved
Table 2 — Mounting dimensions for ball screw nuts and mounting bolts – Series 1
Axial
Ball Lubri- load
Nom- Ball Mounting Flange Flange Thread Tight-
Nom- screw Centering Flat cation at the
inal screw bolt pitch mount- outer Collar Flange for Mount- ening
inal nut diameter flange port opening

diame- nut outer circle di- ing bolts diame- length length lubrica- ing bolts torque of

lead flange length width thread limit of
ter diameter ameter diameter ter tion port one bolt
type length the nut
flange
b b
d P D D D D L L L L L Q Fa max T
0 ho 1 4 5 6 1 3 7 8 10 a
(mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (kN) (Nm)
min. max. min. stat.
4 ≥1 11 17 3,4 23 5 5 4 15 ― ― M3 3,63 1,4
5 ≥1 12 18 3,4 24 5 5 4 15 ― ― M3 3,63 1,4
6 ≥1 12 18 Fig. 3, 3,4 24 10 10 6 16 ― ― M3 4,46 1,4
8 ≥1 16 22 Type B4 3,4 28 10 10 6 19 ― ― M3 4,46 1,4
10 ≥1 19 28 4,5 36 10 12 6 23 ― ― M4 8,16 3,1
12 ≥2 24 32 4,5 40 10 14 8 26 ― ― M4 8,91 3,1
14 ≥2 26 38 5,5 48 10 10 10 40 8 M6 × 1 M5 23,6 6,3
16 ≤ 5 28 38 5,5 48 10 10 10 40 8 M6 × 1 M5 23,6 6,3
16 > 5 32 42 5,5 52 10 15 10 40 8 M6 × 1 M5 23,6 6,3
20 ≥ 1 36 47 Fig. 1 6,6 58 10 16 10 44 8 M6 × 1 M6 34,2 11
25 ≤ 5 40 51 Type B6 6,6 62 10 10 10 48 8 M6 × 1 M6 34,2 11
25 > 5 40 51 6,6 62 10 17 10 48 8 M6 × 1 M6 34,2 12
28 ≥ 4 46 65 9 80 10 10 12 62 8 M6 × 1 M8 66,1 26
32 ≤ 10 50 65 9 80 10 10 12 62 8 M6 × 1 M8 66,1 26
32 > 10 56 71 9 86 20 20 14 65 8 M6 × 1 M8 67,4 26
36 ≥4 61 76 9 91 10 17 14 68 10 M8 × 1 M8 89,9 26
40 < 10 63 78 Fig. 2 9 93 10 17 14 70 10 M8 × 1 M8 89,9 26
40 ≥ 10 63 78 Type B8 9 93 20 20 14 70 10 M8 × 1 M8 89,9 26
40 > 10 ● 70 85 9 100 25 25 14 75 10 M8 × 1 M8 89,9 26
45 ≥ 5 70 88 11 105 20 25 16 80 10 M8 × 1 M10 148 51
50 ≤ 10 75 93 11 110 10 17 16 85 10 M8 × 1 M10 148 51
50 > 10 75 93 11 110 20 20 16 85 10 M8 × 1 M10 148 51
---------------------- Page: 13 ----------------------
ISO/DIS 3408-2:2020(E)
© ISO 2020 – All rights reserved 9
Table 2 (continued)
Axial
Ball Lubri- load
Nom- Ball Mounting Flange Flange Thread Tight-
Nom- screw Centering Flat cation at the
inal screw bolt pitch mount- outer Collar Flange for Mount- ening
inal nut diameter flange port opening

diame- nut outer circle di- ing bolts diame- length length lubrica- ing bolts torque of

lead flange length width thread limit of
ter diameter ameter diameter ter tion port one bolt
type length the nut
flange
b b
d P D D D D L L L L L Q Fa max T
0 ho 1 4 5 6 1 3 7 8 10 a
(mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (kN) (Nm)
min. max. min. stat.
50 > 10 ● 82 100 11 118 25 25 16 92 10 M8 × 1 M10 147 51
63 ≤ 10 90 108 11 125 10 17 18 95 10 M8 × 1 M10 150 51
63 > 10 95 115 13,5 135 25 30 20 100 10 M8 × 1 M12 226 87
63 > 10 ● 105 125 Fig. 2 13,5 145 25 30 20 110 10 M8 × 1 M12 226 87
80 ≤ 10 105 125 Type B8 13,5 145 12 17 20 110 10 M8 × 1 M12 226 87
80 > 10 125 145 13,5 165 25 30 25 130 10 M8 × 1 M12 230 87
80 > 10 ● 135 155 13,5 175 25 40 25 140 10 M8 × 1 M12 230 87
100 ≤10 125 145 13,5 165 10 17 22 130 10 M8 × 1 M12 227 87
100 > 10 150 176 17,5 202 25 30 30 155 10 M8 × 1 M16 440 210
100 > 10 ● 160 186 17,5 212 40 40 30 165 10 M8 × 1 M16 440 210
125 ≤10 150 176 17,5 202 10 17 25 155 10 M8 × 1 M16 434 210
125 > 10 170 196 17,5 222 25 30 30 175 10 M8 × 1 M16 440 210
125 > 10 ● 200 233 22 265 40 45 30 205 10 M8 × 1 M20 714 430
160 ≤ 10 185 212 Fig. 2 17,5 240 10 17 30 190 10 M8 × 1 M16 437 210
160 > 10 210 243 Type B8 22 275 25 30 40 215 10 M8 × 1 M20 728 430
160 > 10 ● 260 300 22 340 40 50 40 265 10 M8 × 1 M20 707 430
---------------------- Page: 14 ----------------------
ISO/DIS 3408-2:2020(E)
10 © ISO 2020 – All rights reserved
Table 2 (continued)
Axial
Ball Lubri- load
Nom- Ball Mounting Flange Flange Thread Tight-
Nom- screw Centering Flat cation at the
inal screw bolt pitch mount- outer Collar Flange for Mount- ening
inal nut diameter flange port opening
diame- nut outer circle di- ing bo
...