Choose a Coating Hardness Tester – Selection Guides
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Choose a Coating Hardness Tester
Checkline Europe's Technical Support
10 Jul 2026
For coatings, the practical hardness tester is a pencil-hardness instrument: a graded set of pencils, drawn across the cured film at a controlled angle and load, gives a fast, standardised scratch-and-gouge grade. The choice is less about competing models than about getting the procedure and the pencil set right, so this guide focuses on what makes a pencil-hardness result defensible.
1. How to Choose
- Conformance to the named standard. A tester that controls the 45° angle and fixed load to ASTM D3363 or ISO 15184 makes the report defensible; a freehand or generic scratch tool does not.
- Pencil-set quality and traceability. The result is only valid if the pencils are from a recognised graded set, supplied and replaceable as a controlled consumable — office-grade pencils invalidate the report.
- Repeatability across operators. The biggest source of disagreement between sites is operator technique, so a self-stabilising frame that fixes the angle and load removes most of that variability.
- Cure state before testing. Test only after the coating's full cure time; freshly cured parts read softer and drift upward over the next 24 to 72 hours.
- Do not buy it as a substitute for thickness, adhesion or holiday testing when those are the actual decision points.
2. Product to Consider
- PosiTest PG for pencil hardness testing when this method fits the coating check you need to perform.
3. Next Step
Start with Coating Hardness Testers to review the full range, then look at PosiTest PG if pencil hardness is the right method for your coating checks.