No. 017 for Shot blasting
No. 018 Grit-blasting
These two comparators are specially designed to check the roughness of steel surfaces which have been blast cleaned to cleanliness grades SA 2.5 and SA 3 in preparation for painting. They conform to ISO 8503.

Typical Applications of our comparison specimens:

• checking roughness of turned, milled, ground, reamed, polished or lapped parts during machining
• checking the roughness of spark-eroded surfaces as described in the VDI 3400 Guideline
• checking the roughness of steel surfaces which have been prepared for painting by blast-cleaning, as outlined in ISO 8503
• checking the seriousness of damage to parts caused by nicks, dents and scratches
• checking reconditioned ship propeller blades