ISO 6313:1980

Overview

ISO 6313:1980 - "Road vehicles - Brake linings - Effects of heat on dimensions and form of disc brake pads - Test procedure" specifies a combined laboratory method to measure dimensional changes of disc brake pads with temperature and their resistance to heat transfer. Intended for road-vehicle disc brake pads (integral moulded or bonded type, solid backing plate) whose finished dimensions do not exceed 80 mm depth × 120 mm width × 20 mm thickness, the standard defines sample preparation, test rig requirements, heating cycles, measurement points and reporting requirements.

Key topics and requirements

• Scope and applicability
  • Applies to disc brake pads for road vehicles with the dimensional limits above.
  • Terminology references ISO 611.
• Sample preparation
  • Samples taken from stock; rubbing with emery paper (grain No. 120) to remove paint and smooth surfaces.
  • Remove friction material from spigot holes to avoid affecting results.
• Test rig and heating
  • Rigid electrically heated steel plate (example size 80 × 170 × 40 mm).
  • Heating source capable of raising plate to 400 °C in 10 ± 0.5 minutes (higher final temp allowed if required for a vehicle type).
  • Clamping block with a 48 mm diameter piston, coil springs and screw adjuster to apply a compressive force range 20–200 N; typical pad surface pressure ≈ 20 kPa (0.02 N/mm²).
  • For pads with anti-noise strips, a 4 mm thick, 80 × 100 mm thermal-conductive intermediate plate is used.
• Instrumentation and measurements
  • Drill two 2 mm holes (lining and backing plate) parallel to rubbing surface, 5 mm from contact surface, to house sheathed thermocouples (omitted where thin anti-noise strips prevent drilling).
  • Measure pad thickness at two reference points (mean value d̄) to 0.01 mm accuracy.
  • Record heater plate temperature, pad temperature and backing/intermediate plate temperature during heating and cooling.
  • Readings recorded continuously (recorder) or at 25 °C intervals between 50 °C and final temperature if manual.
• Test cycles and reporting
  • Two heating periods (heat to final temp, cool naturally, repeat without readjustment).
  • Report shall include product ID, mean thickness before test, maximum relative thickness changes with temperatures, residual changes at room temperature, backing/intermediate plate temps, and appearance (cracks, bubbling, delamination).

Applications and users

• Who uses it: brake manufacturers, OEM qualification engineers, materials and reliability labs, quality control and certification bodies.
• Practical value:
  • Validate dimensional stability of friction linings under thermal load.
  • Assess heat transfer through pad assembly and backing plate.
  • Prevent brake malfunction from thermal deformation (outline changes, delamination).
  • Support material selection, design verification and quality acceptance testing.

Related standards

• ISO 611 (Braking of motor vehicles - Terminology) for definitions and terminology.
• Developed by ISO/TC 22 (Road vehicles).