ISO 22574:2023

Overview

ISO 22574:2023 - Road vehicles - Brake linings friction materials - Visual inspection defines the visual criteria used to identify and assess product characteristics of brake friction materials for quality control and for commercial and technical agreements. Inspection is performed on unused, “as supplied” products. The standard covers disc brake pads, drum brake linings and bonded lined shoes, and for the first edition includes product characteristics of metal lining carriers (backing plates, bonded shoes). Acceptance criteria are intended to exclude any visual defects that could affect the function or performance of brake linings, unless alternate customer–supplier agreements are made.

Key Topics and Requirements

• Scope and intent: Visual aspects for identification and assessment of friction materials; sequence of characteristics is not a priority order.
• Inspection condition: Visual inspection in the unused, “as supplied” state.
• Size-based differences: Some criteria differ for disc pads with effective lining area < 120 cm² versus ≥ 120 cm².
• Acceptance principle: Criteria exclude any characteristics likely to impact function or safety of brake linings.
• Characteristic features detailed (examples extracted from the standard):
  • Gapping between friction material and plate; edge chipping limits.
  • Splits, deep splits and minor splits.
  • Defects around spigots, holes and drill locations (plucked/indented spigots, pinholes, burrs).
  • Excess adhesive, material flash, abrasive/anti-noise coating defects.
  • Surface issues: blisters, porosity, grinding marks, cold laps, contamination and foreign-matter inclusion.
  • Carrier/plate defects: scratched plates, dents, spring holder defects and deformation from blanking.
  • Drum lining specifics: chip/corner damage, moulding skin, rivet/drill-hole cracks, pitted surfaces.
  • Bonded lined shoe specifics: lining overhang, excess adhesive exudation, gaps between lining and shoe platform, restricted lever movement.
• No normative references are listed within ISO 22574:2023 (the document itself cites no mandatory external standards).

Applications and Who Uses It

• Manufacturers of brake linings and backing plates: set production and incoming quality inspection criteria.
• Automotive OEMs and tier suppliers: define acceptance for commercial and technical agreements, supplier audits and draw-offs.
• Quality engineers and laboratory inspectors: implement standardized visual inspection procedures to ensure safety and interchangeability.
• Purchasing and conformity teams: use acceptance criteria in contracts to prevent delivery of components with functional visual defects.
• Aftermarket and remanufacturing operations: apply the standard to verify components meet minimum visual quality for safe service.

Related Standards (if applicable)

• ISO 22574:2023 contains no normative references. For complementary requirements, consult other ISO road-vehicle and braking system standards produced by ISO/TC 22 (e.g., standards covering performance, testing and materials for braking systems).

Keywords: ISO 22574:2023, brake linings, friction materials, visual inspection, disc brake pads, drum brake linings, bonded lined shoes, acceptance criteria, backing plates, metal lining carriers.