SIST EN ISO 20567-2:2023 PDF

Overview

EN ISO 20567-2:2023 - “Paints and varnishes - Determination of stone‑chip resistance of coatings - Part 2: Single‑impact test with a guided impact body” - is an international/CEN‑endorsed method for evaluating the resistance of automotive finishes and other coatings to stone‑impact damage. Published in 2023 (third edition), this standard defines a reproducible single‑impact test that simulates stone‑chip damage using a wedge‑shaped guided impact body driven by a compressed‑air propelled steel ball.

Key topics and technical requirements

• Scope and purpose: Assessment of stone‑chip resistance of coatings by producing a delamination pattern equivalent to multi‑impact tests.
• Test principle: A wedge‑shaped impact body is pushed into the coating by energy transferred from a compressed‑air accelerated steel ball; loose fragments are removed and the total width of delamination (including the wedge mark) is measured.
• Apparatus: Single‑impact tester with a guided wedge impact body (impact body material: hardened steel, 60–66 HRC). A steel ball (mass less than the impact body) is accelerated by compressed air (nominal 300 kPa / 3 bar).
• Impact body life: The impact body shall be checked and replaced if necessary after a maximum of 500 test runs or at the end of a test series that reaches 500 impacts at the same contact point.
• Test panels: Minimum panel size 100 mm × 100 mm, substrate thickness at least 0.7 mm. Panels must be prepared per ISO 1514 and coated using the manufacturer’s application method.
• Coating thickness: Measured in micrometres by methods in ISO 2808.
• Procedure elements: Calibration, conditioning (refer to ISO 3270 for temperature/humidity), test conditions, number of runs, removal of loose paint, and result evaluation.
• Evaluation & precision: Results are reported as total delamination width; the standard addresses precision (repeatability and reproducibility) and requires calibrated equipment (see normative Annex B).

Applications and users

• Primary users: Automotive manufacturers, OEM paint labs, coating formulators, independent testing laboratories, and quality assurance teams.
• Use cases:
  • Comparative performance testing of paints, clearcoats and multi‑layer automotive systems.
  • Validation of new formulations or process changes (application, curing).
  • Supplier qualification and acceptance testing for stone‑chip resistance claims.
  • R&D screening to correlate lab impact behavior with field performance.
• Practical value: Provides a standardized, repeatable method to quantify susceptibility to stone chipping, enabling objective comparisons and quality control.

Related standards

• ISO 20567 series (multi‑ and other single‑impact tests): ISO 20567‑1 (multi‑impact), ISO 20567‑3 (other single‑impact variant).
• Test panel and conditioning references: ISO 1514, ISO 2808, ISO 3270.
• Material reference for substrates: EN 573‑3 (aluminium alloys).

Keywords: stone‑chip resistance, paint testing, single‑impact test, ISO 20567‑2:2023, coatings, automotive finishes, impact tester, wedge impact body.