Overview
EN ISO 15695:2001 (identical to ISO 15695:2000 with Technical Corrigendum 1:2000) defines a test method for determining the scratch resistance of vitreous and porcelain enamel finishes. The standard measures the durability of enamel coatings against scratching by sharp objects under relatively high forces. It is a performance test for enamelled metal substrates and is distinct from “scratch hardness” tests (see EN 101 / Mohs method).
Key topics and technical requirements
- Scope: Test method for enamel finishes on metal substrates prepared according to ISO 2723 (sheet steel), ISO 2724 (cast iron) or ISO 13804 (aluminium).
- Minimum coating thickness: enamel layer at least 50 µm.
- Apparatus:
- Turntable (radius ≥ 50 mm) able to make one revolution in 10–13 s and stop automatically.
- Diamond indenter: cone angle 90° ± 1°, tip curvature radius 90 µm ± 3 µm; crystallographic axis aligned with holder.
- Force application from 0 N to 10 N with 0.1 N precision.
- Felt pens in red, green, blue and black (identical manufacture); inks must meet a color change limit after wiping (dE* ≤ 10 per ISO 7724-3).
- Procedure (summary):
- Produce circular scratches at stepwise forces (highest forces on outer circles), circles typically between 25 mm and 45 mm radius.
- Colour each scratched circle with the designated felt-pen colours, allow ink to dry ≥ 1 min, then wipe.
- Determination:
- Visually inspect at 25 cm under 500–800 lx illumination (Technical Corrigendum).
- Scratch resistance = highest force (N) at which the felt-pen colour remains over less than 50% of the tested length for each colour. Repeat determination if ambiguous.
- Test report must include reference to ISO 15695, specimen description (material), scratch resistance in Newtons, and test date.
Applications
- Quality control and acceptance testing for porcelain enamel coatings on cookware, domestic appliances, sanitaryware, industrial vessels, and coated components.
- Product development and comparative durability testing of enamel formulations and application processes.
- Verification of enamel performance for safety, lifecycle and warranty specifications.
Who uses this standard
- Enamel manufacturers and coaters
- Coating/process engineers and R&D laboratories
- Third‑party test labs and certification bodies
- Quality assurance teams in appliance, sanitaryware and industrial equipment manufacturing
Related standards
Keywords: EN ISO 15695:2001, ISO 15695, scratch resistance, porcelain enamel, vitreous enamel, enamel finishes, scratch test, diamond indenter, coating durability.