ISO 19252:2025

Overview

ISO 19252:2025 - Plastics - Determination of scratch properties specifies a standardized laboratory method to determine how plastic materials respond to scratching under defined conditions. The standard covers test principles, apparatus, specimen preparation, test procedures and result reporting. It supports two main approaches: constant-load testing (to classify scratch behaviour and create a scratch map) and linearly increasing load testing (to determine the critical normal load). This second edition updates material scope and test details and supersedes ISO 19252:2008.

Key topics and technical requirements

• Scope of materials: thermoplastic moulding, extrusion and casting materials (filled/reinforced and unfilled), thermosetting moulding materials (including compounds), thermosetting sheets and rigid thermoplastic materials.
• Test principle: a defined scratch tip is moved across a specimen under specified test load (P) and test speed (v) while recording scratch force (Fs) and scratch-tip displacement (d).
• Scratch behaviour classification: three types - ploughing (p), wedge formation (w) and cutting (c) - defined by characteristic force/displacement signals and surface features.
• Outputs:
  • Scratch map: comparative data showing scratch behaviour over combinations of load and speed.
  • Critical normal load: load at which a transition in scratch behaviour occurs (from an alternative linearly increasing load test).
• Apparatus and specimen requirements: standardized test machine components (frame, scratch tip geometry, load application, speed control, specimen support, force indicator, displacement gauge), preferred specimen dimensions and preparation/conditioning per referenced standards.
• Test conditions and data recording: specified test atmosphere (ISO 291), recording of Fs, d, scratch distance, optional monitoring/inspection (photographic examples in annexes).

Practical applications and users

ISO 19252:2025 is used to:

• Evaluate scratch resistance of plastics and polymer-based components.
• Support material selection and comparative screening (via scratch maps) in product development.
• Provide reproducible test data for quality control, supplier specifications and failure analysis. Typical users:
• Materials scientists and polymer testing laboratories
• Quality assurance teams in automotive, consumer electronics, medical devices and coatings industries
• Product designers and materials engineers comparing surface durability

Related standards

• ISO 291 - Standard atmospheres for conditioning and testing
• ISO 294-1 - Injection moulding test specimens (thermoplastics)
• ISO 10724-1 - Injection moulding of thermosetting powder moulding compounds
• ISO 20753 - Plastics - Test specimens

Keywords: ISO 19252, scratch properties, scratch testing, scratch resistance, scratch map, critical normal load, plastics testing, scratch behaviour, thermoplastic, thermosetting.