ISO 6312:2010

Road vehicles — Brake linings — Shear test procedure for disc brake pad and drum brake shoe assemblies

ISO 6312:2010 specifies a method for measuring the strength of the bond connection between the lining material and the carrier in disc brake pad and drum brake shoe assemblies (shear strength). ISO 6312:2010 is applicable to assemblies that are integrally moulded, bonded or that use mechanical retention systems (MRS) of both types used for brakes on road vehicles. ISO 6312:2010 does not apply to riveted assemblies.

Véhicules routiers — Garnitures de freins — Méthode d'essai de cisaillement des ensembles de plaquettes de freins à disque et segments de freins à tambour

General Information

• Status: Published
• Publication Date: 10-Aug-2010
• ICS: 43.040.40 - Braking systems
• Technical Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Drafting Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Current Stage: 9093 - International Standard confirmed
• Start Date: 16-Aug-2023
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 6312:2001 - Road vehicles — Brake linings — Shear test procedure for disc brake pad and drum brake shoe assemblies
• Effective Date: 15-Apr-2008

Overview

ISO 6312:2010 - "Road vehicles - Brake linings - Shear test procedure for disc brake pad and drum brake shoe assemblies" defines a standardized method to measure the shear strength of the bond between friction lining and carrier in brake pad and shoe assemblies. It covers integrated (moulded), bonded and mechanical retention systems (MRS) used on road-vehicle brakes, and explicitly excludes riveted assemblies.

Key topics and technical requirements

• Objective: Measure the load at failure (shear force F) and compute shear strength τ = F / A, where A is the bond area at the bond line.
• Samples: Test full assemblies or coupons/sections; five samples recommended for standard testing. Specify orientation (radial or tangential) when using sections.
• Test conditions: Ambient testing at (23 ± 5) °C by default. Optional elevated-temperature tests with defined dwell and temperatures (typical recommendations: ~200 °C for drum linings, ~300 °C for disc pads).
• Load application: Controlled average load rate of (4 500 ± 1 000) N/s or, for constant-crosshead machines, 10 ± 1 mm/min. Avoid shock loads.
• Fixtures and tooling: Loading tool radius ≤ 2 mm; tool contact within (1 ± 0.2) mm of the carrier/backplate. Disc pad fixtures require a face load of (0.5 ± 0.15) N/mm of lining area (to prevent movement) while minimizing friction influence.
• Failure assessment: Record failure load and shear pattern (percentages of clean carrier, adhesive failure, or failure within lining). Optional chemical staining test (CuSO4/NaCl/HCl solution) to distinguish fracture surfaces.
• Reporting: Include supplier and batch ID, sample type and orientation, number of samples, minimum and mean shear strength (MPa), shear pattern percentages, test deviations and tooling details.

Applications and users

ISO 6312:2010 is used to:

• Validate manufacturing processes for brake linings (bond integrity).
• Compare material formulations and retention methods (bonded vs. MRS).
• Support quality control, product development and supplier qualification.
• Assess effects of service or conditioning (e.g., after ISO 6314 treatments or dynamometer testing).

Typical users:

• Brake component manufacturers and OEMs
• Material and adhesive suppliers
• Test laboratories and certification bodies
• R&D and quality assurance teams in the automotive industry

Related standards

• ISO 6314 - Test procedures for resistance to liquids (water, saline, oil, brake fluid)
• ISO 15484 - Brake lining product definition and quality assurance
• ISO 611 - Braking vocabulary (terms referenced by ISO 6312)

ISO 6312:2010 provides a reproducible shear test method to benchmark bond performance of disc pads and drum shoes, helping manufacturers, test labs and OEMs ensure safe, consistent brake-lining attachment and performance.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 6312
Third edition
2010-08-15
Road vehicles — Brake linings — Shear
test procedure for disc brake pad and
drum brake shoe assemblies
Véhicules routiers — Garnitures de freins — Méthode d'essai de
cisaillement des ensembles de plaquettes de freins à disque et
segments de freins à tambour
Reference number
©
ISO 2010
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ii © ISO 2010 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Symbols and units.2
5 Sampling and conditioning .2
6 Test rig and fixtures .2
6.1 Test rig.2
6.2 Fixtures.3
7 Test procedure.5
8 Calculation of shear strength.6
9 Presentation of results.6
Annex A (normative) Test procedure flowchart.8
Annex B (informative) Test report .10
Bibliography.11

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 6312 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking
systems and equipment.
This third edition cancels and replaces the second edition (ISO 6312:2001), which has been technically
revised.
iv © ISO 2010 – All rights reserved

Introduction
The shear property relates to stresses at the area of contact between lining and carrier in disc brake pad and
drum brake shoe assemblies.
The specification for the average rate of load and the recommendation for variations in the instantaneous rate
of load given in this International Standard take into account current practice, based upon an examination of
equipment in use.
This third edition of this International Standard incorporates technical updates generated in the course of
harmonization efforts during the development of ISO 15484.

INTERNATIONAL STANDARD ISO 6312:2010(E)

Road vehicles — Brake linings — Shear test procedure for disc
brake pad and drum brake shoe assemblies
1 Scope
This International Standard specifies a method for measuring the strength of the bond connection between the
lining material and the carrier in disc brake pad and drum brake shoe assemblies (shear strength). This
International Standard is applicable to assemblies that are integrally moulded, bonded or that use mechanical
retention systems (MRS) of both types used for brakes on road vehicles. This International Standard does not
apply to riveted assemblies.
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 611, Road vehicles — Braking of automotive vehicles and their trailers — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 611 and the following apply.
3.1
lining
friction material component of a brake lining assembly
3.2
carrier
component of a brake lining assembly to which the friction material is attached
3.3
bond area
A
contact area between lining and carrier
3.4
mechanical retention system
MRS
attachment method where mechanical protrusions on the backing plate aid the retention of the friction material
or the underlayer
3.5
shear force at failure
F
total load applied at the time of shear failure
3.6
shear strength at failure
τ
ratio of the load at failure divided by the bond area
4 Symbols and units
The symbols and preferred units used in this International Standard are given in Table 1. See Clause 8.
Table 1 — Symbols and units
Quantity Symbol Unit
Shear force at failure F N
Bond area A mm
Shear strength at failure τ MPa

5 Sampling and conditioning
This procedure can also apply for samples during product development, on finished products, or after special
treatment (such as that covered by ISO 6314) or usage (inertia-dynamometer testing or field use) with the
appropriate preparation.
Perform the testing on a complete assembly or a section (coupon) of the assembly. When testing a section or
coupon, apply the load in the radial or tangential direction relative to the vehicle mounting position. Indicate
the test orientation on the test report.
If needed, prepare the sample edges to ensure good contact with the loading and fixed tools. Remove noise
insulating shims before the test.
When testing a lined shoe, the test area may cover the full assembly or segments of an assembly confined by
saw cutting down to the carrier (see Figure 1).
Use five samples for standard testing.
NOTE The test procedure applies a load in a direction that might not be in ac
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