ISO 23848-1:2009

Machine tools - Ball splines - Part 1: General characteristics and requirements

ISO 23848-1:2009 specifies and standardizes the following characteristics for ball splines: - the shapes and dimensions; - the test methods; - the inspection; - the designation; - the marking.

Machines-outils — Guidages cannelés à billes — Partie 1: Exigences et caractéristiques générales

General Information

• Status: Published
• Publication Date: 05-Nov-2009
• ICS: 25.060.99 - Other machine tool systems
• Technical Committee: ISO/TC 39 - Machine tools
• Drafting Committee: ISO/TC 39 - Machine tools
• Current Stage: 9020 - International Standard under periodical review
• Start Date: 15-Oct-2025
• Completion Date: 15-Oct-2025

Overview

ISO 23848-1:2009 - "Machine tools - Ball splines - Part 1: General characteristics and requirements" sets international requirements for the geometric, mechanical and inspection-related characteristics of ball splines used in machine tools. The standard standardizes shapes and dimensions, test methods, inspection procedures, designation and marking for ball spline assemblies (spline shaft, spline outer race, balls, recirculation devices and seals).

Key topics and technical requirements

• Classification and grades: Ball splines are classified as type A (angular) or type R (radial) and divided into three precision grades: C1, C3 and C5 (symbols P, H or no symbol respectively).
• Shapes & dimensions: Nominal spline shaft diameters and outer-race boundary dimensions are specified (see Annex A).
• Groove twist: Tolerance on groove twist is defined and measured over a 100 mm travel (Table 2). Example maximum twist tolerances: C1 = 6 µm, C3 = 13 µm, C5 = 33 µm.
• Runout and accuracy: Radial and axial runout limits for spline grooves, part-mounting journals and outer races are provided (Tables 3–8). Total radial runout of the spline shaft relative to support journals is tabulated by nominal diameter and shaft length.
• Hardness: Minimum hardness for spline groove surfaces is specified as W 653 HV (≈ W 58 HRC).
• Test methods & environment: Standardized measurement methods are given for groove twist, runout and hardness; testing is performed under standard atmosphere 20 °C (ISO 554, class 15).
• Inspection, designation and marking: Procedures for inspection acceptance, standardized designation formats and marking requirements are included to ensure traceability and interchangeability.

Applications and users

ISO 23848-1 is essential for:

• Machine tool designers and OEMs specifying ball spline components for linear-plus-rotary motion systems.
• Ball spline manufacturers establishing product specifications and quality control procedures.
• Quality and metrology engineers performing acceptance testing and inspection.
• Procurement/specification engineers who require standardized designation and marking for component interchangeability.

Practical applications include precision feeds in CNC machines, linear actuators with torque transmission, robotics, and other systems requiring smooth axial translation while transmitting torque.

Related standards

• ISO 23848-2 - complements Part 1 by specifying dynamic and static load/torque ratings and rating life.
• Normative references used for testing include ISO 554 (standard atmospheres) and ISO 6507-1/2 (Vickers hardness test and calibration).

Keywords: ISO 23848-1, ball splines, machine tools, groove twist, spline shaft, spline outer race, runout, hardness, test methods, inspection, dimensions.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23848-1
First edition
2009-11-15
Machine tools — Ball splines —
Part 1:
General characteristics and requirements
Machines-outils — Guidages cannelés à billes —
Partie 1: Exigences et caractéristiques générales

Reference number
©
ISO 2009
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ii © ISO 2009 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Classification and grade.2
5 Characteristics.4
5.1 Groove twist of the spline shaft.4
5.2 Spline shaft accuracy.4
5.3 Spline outer race mounting accuracy .4
5.4 Total radial runout of the spline shaft in relation to the axis of the support journals .5
5.5 Hardness .5
6 Shapes and dimensions .10
7 Test methods .10
7.1 Test environment.10
7.2 Groove twist.10
7.3 Accuracy of the spline shaft .11
7.4 Accuracy of the spline outer race mounting .13
7.5 Total radial runout of the spline shaft in relation to the axis of the support journals .13
7.6 Hardness .15
8 Inspection.15
9 Designation .15
10 Marking.16
Annex A (normative) Shapes and dimensions of the spline outer races .17

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 23848-1 was prepared by Technical Committee ISO/TC 39, Machine tools.
ISO 23848 consists of the following parts, under the general title Machine tools — Ball splines:
⎯ Part 1: General characteristics and requirements
⎯ Part 2: Dynamic and static load ratings and rating life

iv © ISO 2009 – All rights reserved

Introduction
The ball spline is a power transmission component based on recirculating balls, which is designed to translate
axially while transmitting torque by an anti-friction means. The ball spline is selected for its smooth operation,
high speed capability, low friction and high-radial and high-torsional load capacity.
This part of ISO 23848 specifies and standardizes the following characteristics of ball splines:
⎯ the shapes and dimensions;
⎯ the test methods;
⎯ the inspection;
⎯ the designation;
⎯ the marking.
ISO 23848-2 specifies and standardizes the following properties of ball splines:
⎯ the basic static and dynamic load ratings;
⎯ the basic static and dynamic torque ratings;
⎯ the rating life.
INTERNATIONAL STANDARD ISO 23848-1:2009(E)

Machine tools — Ball splines —
Part 1:
General characteristics and requirements
1 Scope
This part of ISO 23848 specifies and standardizes the following characteristics for ball splines:
⎯ the shapes and dimensions;
⎯ the test methods;
⎯ the inspection;
⎯ the designation;
⎯ the marking.
2 Normative references
The following referenced documents are indispensable for the application 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 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6507-2, Metallic materials — Vickers hardness test — Part 2: Verification and calibration of testing
machines
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE See Figure 1.
3.1
ball spline
machine element consisting of the spline shaft, spline outer race, balls and recirculation devices and seals, for
providing smooth relative axial motion between the shaft and the outer race, while preventing their relative
rotation for the purpose of transmitting torque
3.2
effective spline length
actual available length of axial travel for the spline outer race on the spline shaft
3.3
groove twist of the ball spline
value of rotational deviation of the spline outer race over the effective travel length
3.4
nominal diameter of the spline shaft
outer diameter of the spline shaft representing the size of the ball spline without tolerance, sometimes
expressed as the pitch circle diameter without tolerance
NOTE The pitch circle diameter, D , refers to the diameter specifying the location of the rolling ball centres in the ball
p
spline assembly with their theoretical contacts on the groove surfaces of both the spline shaft and the spline outer race.
3.5
spline groove
groove ground or rolled along the axial direction on the shaft periphery or the inner surface of the spline outer
race to facilitate the smooth rolling of balls inside the assembly
3.6
spline outer race
assembly comprising the body with internal spline grooves, balls, recirculation devices and/or additional
embodiments
3.7
spline shaft
shaft consisting of axial spline grooves, which are matched with the grooves of a compatible spline outer race
and can accommodate recirculating balls
4 Classification and grade
Ball splines shall be classified as type A (angular) or type R (radial), as shown in Figure 1 and Table 1. Each
ball spline type shall be divided into three grades, C1, C3 and C5, according to the quality and precision and
may be represented by symbols such as:
⎯ P for C1;
⎯ H for C3;
⎯ no symbol for C5.
2 © ISO 2009 – All rights reserved

a) Type AI b) Type AII
c) Type R
Key
1 seal
2 keyway
3 spline shaft
4 spline outer race
5 balls
6 retainer and/or end cap
NOTE These drawings are examples of a construction.
Figure 1 — Names of the parts of typical ball splines

Table 1 — Type and symbol of ball splines
Name Type Flange on the spline outer race Seal
without
a
without
one side (U)
AI
with
a
both sides (UU)
Ball spline AII
without
R
a a
with (F) one side (U)
with
a
both sides (UU)
a
Letters in parentheses in this table are indication symbols, the application of which is given in Clause 9.
5 Characteristics
5.1 Groove twist of the spline shaft
The tolerance on the groove twist of a ball spline, when measured by the method given in 7.2, shall meet the
requirement of Table 2 with respect to 100 mm taken at random within the effective spline length.
In cases where it is impossible to take 100 mm or more relative travel distance between the spline shaft and
spline outer race, apply a converted value of Table 2 in proportion to the travel distance.
Table 2 — Groove twist of the ball spline
Dimensions in micrometres
Grade C1 C3 C5
Twist tolerance (max.) 6 13 33
NOTE See Figure 3.
5.2 Spline shaft accuracy
The radial runout of the spline grooves, part mounting journals and the axial runout of the end face of the
spline shaft in relation to the axis of support journals of the spline shaft, when measured by the methods given
in 7.3.1 to 7.3.3, shall meet the specifications in Tables 3 to 5, respectively (see Figures 2, 4, 5 and 6).
5.3 Spline outer race mounting accuracy
The axial runout of the spline outer race reference face or the flange mounting face of the flange, and the
radial runout of the spline outer race in relation to the axis of the spline shaft, when measured using the
methods given in 7.4.1 and 7.4.2, shall meet the specifications in Tables 6 and 7, respectively (see Figures 2,
7 and 8).
NOTE Figures 2 to 9 typically show type AI, as an example.

4 © ISO 2009 – All rights reserved

Key
1 part mounting journal
2 spline groove
3 spline outer race
4 support journal
5 spline shaft
NOTE 1 The support journals refer to the portions, where bearings will support the spline shaft.
NOTE 2 The part mounting journals refer to the portions intended for mounting a gear wheel or other machine
elements.
NOTE 3 Not applicable to those without support journals and/or part mounting journal.
Figure 2 — Accuracy of the ball spline
5.4 Total radial runout of the spline shaft in relation to the axis of the support journals
The tolerance on the total radial runout of the spline shaft in relation to the axis of the support journals, when
measured using the method given in 7.5, shall meet the specifications in Table 8 (see Figures 2 and 9).
5.5 Hardness
The hardness of spline groove surfaces, when determined according to the method given in 7.6, shall be at
least W 653 HV (W 58 HRC).
Table 3 — Radial runout of the spline grooves in relation to the axis of the support journals
Runout tolerance
Nominal diameter, d µm
a
mm
max.
Grade
Over Up to and including C1 C3 C5
— 8 8 14 33
8 12 10 17 41
12 20 12 19 46
20 32 13 22 53
32 50 15 25 62
50 80 17 29 73
80 125 20 34 86
NOTE See Figure 4.
a
As the influence of the runouts of the axis of the spline shaft is included in this value, a correction is needed. For the correction,
obtain the correction value from Table 8 for the total runout tolerance on the shaft support journals corresponding to the ratio of the total
shaft length to the measured distance between the points of support and add it to the tolerance in Table 3 to apply.

Table 4 — Radial runout of the part mounting journals in relation to the axis of the support journals
Runout tolerance
Nominal diameter, d µm
mm
max.
Grade
Over Up to and including C1 C3 C5
— 8 8 14 33
8 12 10 17 41
12 20 12 19 46
— — — — —
20 32 13 22 53
32 50 15 25 62
50 80 17 29 73
80 125 20 34 86
NOTE See Figure 5.
6 © ISO 2009 – All rights reserved

Table 5 — Axial runout of the end faces of the spline shaft in relation to the axis of the support
journals
Runout tolerance
Nominal diameter, d µm
mm
max.
Grade
Over Up to and including C1 C3 C5
— 8 6 9 22
8 12 6 9 22
12 20 8 11 27
— — — — —
20 32 9 13 33
32 50 11 16 39
50 80 13 19 46
80 125 15 22 54
NOTE See Figure 6.
Table 6 — Axial runout of the spline outer race reference face or the flange mounting face in relation
to the axis of the spline shaft
Runout tolerance
Nominal diameter of the spline outer race,
µm
D
max.
mm
Grade
Over Up to and including C1
...