Overview
EN ISO 6272-2:2011 - Paints and varnishes - Rapid‑deformation (impact resistance) tests - Part 2: Falling‑weight test, small‑area indenter (ISO 6272-2:2011) describes a laboratory method to evaluate the resistance of a dry paint or varnish film on a metal substrate to cracking or peeling when subjected to a rapid deformation produced by a falling weight acting on a small‑area spherical indenter. The standard emphasizes that the apparatus produces rapid deformation rather than a true high‑velocity impact and cautions about limited reproducibility.
Key topics and technical requirements
- Test principle: A cylindrical weight is dropped down a vertical guide tube to strike a hardened‑steel hemispherical indenter that rests on the coated panel; failure is detected as cracking or peeling.
- Apparatus essentials: guide tube (0.6–1.2 m), weights of (1000 ±10) g or (2000 ±20) g, indenter mass (150 ±15) g with hemispherical head diameters of (12.7 ±0.06) mm or (15.9 ±0.06) mm, panel support with a central hole Ø (16.3 ±0.1) mm.
- Specimen preparation: metal panels per ISO 1514, minimum 0.25 mm thick, test positions at least 40 mm apart and ≥20 mm from edges; dry‑film thickness measured per ISO 2808 and must be within ±10% of the specified value.
- Conditioning and test environment: condition at (23 ±2) °C and (50 ±5)% RH (minimum 16 h) and complete testing within 30 minutes after removal; record test temperature and relative humidity.
- Procedure highlights: increase drop height in 25 mm increments to determine the height where cracking/peeling first appears; perform repeated drops (five impacts at specified heights) at randomized positions; inspect with a ×10 magnifier or, on steel, with acidified copper sulfate to make failure more visible.
- Precision and limitations: due to poor interlaboratory reproducibility, numerical results should generally come from a single laboratory; interlaboratory comparisons are more reliable when using ranking instead of absolute values.
Applications
- Quality control and batch acceptance testing of coating systems on metal substrates.
- R&D and formulation screening to compare impact/rapid‑deformation resistance of paints, varnishes and multilayer systems.
- Failure analysis when coatings crack or peel under localized deformation (e.g., dropped objects, tooling contact).
- Specification and material selection in industries where small‑area mechanical deformation of coated surfaces is a concern (automotive, appliance, metal fabrication, protective coatings).
Who uses this standard
- Coating manufacturers and formulators
- Independent and in‑house test laboratories
- Quality assurance and coating specification engineers
- OEMs, asset owners and corrosion/control engineers
Related standards
Keywords: EN ISO 6272-2:2011, impact resistance test, falling‑weight test, small‑area indenter, paints and varnishes, rapid‑deformation test, coating testing.
