Standard · Adhesion, cure and holidays
ISO 2409
The cross-cut test for adhesion.
A cutting tool makes a lattice of cuts through the coating to the substrate. Tape is applied over the lattice and pulled off, and the result is classified by how much coating came away, from 0 (cut edges smooth, nothing detached) to 5.
Cut spacing
Six cuts each way. The spacing follows the total thickness: up to 60 µm, 1 mm on hard substrates and 2 mm on soft ones; 61–120 µm, 2 mm; 121–250 µm, 3 mm. Above 250 µm, or on a textured coating, the test does not suit: use an X-cut (ISO 16276-2) or pull-off (ISO 4624).
A valid test
- Every cut must reach and mark the substrate. If the coating is too hard to cut through, the test is invalid and is reported as such.
- In the field, measure and record the ambient conditions.
- Routine testing is one determination. For more precision, test at least three places; if they differ by more than one class, test again at more places.
What it does not do
ISO 2409 itself says the cross-cut is not a means of measuring adhesion. For a value in MPa, use the pull-off test of ISO 4624.
Note: the cross-cut test is a destructive test and is outside the CIP 1 syllabus.
5 practice items in the members area mention ISO 2409 (CIP 2: 3 · FROSIO written: 2).
Related
Try it in an exam-style question. The free readiness check shows the question style, explains every answer and gives you a dated study plan.
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Also published openly: Gardco: PosiTest CH cross-hatch kit, ISO 2409 blade spacing.
This page describes the subject of ISO 2409 in our own words; it does not reproduce the standard. For the full text, buy the current edition from ISO. Checked on 2026-10-14; errors go in the corrections log. CoatMentor is an independent study aid. It is not affiliated with ISO, AMPP, SSPC, NACE International, ASTM or FROSIO.