D2794 — Impact Test Astm

This test is critical for industries where coated metal parts are exposed to mechanical abuse during manufacturing, assembly, transportation, or end-use (e.g., automotive body panels, appliances, coil-coated siding, drum coatings).

1. Overview and Scope ASTM D2794 is a standardized test method used to determine the resistance of a dry, cured organic coating (paint, lacquer, varnish, or related product) to cracking or detachment from a metal substrate when subjected to sudden, rapid deformation (impact). impact test astm d2794

A weighted, hemispherical-tipped indenter (diameter: 0.625 in or 15.9 mm) is dropped from a specific height onto the coated side (or reverse side) of a test panel, causing rapid indentation. The coating is then evaluated for cracking or loss of adhesion. This test is critical for industries where coated

is the closest direct replacement. However, results between D2794 and ISO 6272-1 are not directly interchangeable due to differences in indenter/die geometry and panel clamping. 11. Practical Applications & Typical Values | Coating type | Typical reverse impact (in·lb) | Notes | |--------------|-------------------------------|-------| | General industrial enamel | 20–40 | Often fails at lower end | | Automotive clearcoat | 40–80 | Requires very flexible chemistry | | Polyester coil coating | 80–160 | High flexibility for post-forming | | Epoxy powder coating | 80–120 | Thicker films (2–4 mils) | | High-build polyurethane | 100–160 | Impact modifiers added | | PVDF (Kynar) | 120–180 | Extremely flexible | A weighted, hemispherical-tipped indenter (diameter: 0