Shot Blasting/ Grit Blasting Comparators

Shot Blasting/ Grit Blasting Comparators

In cases where surface roughness needs to be measured with great precision, elaborate instruments must be used. These are expensive, and often unsuitable for workshop use, where roughness of machined surfaces can usually be assessed conveniently and with sufficient reliability using visual and tactile (fingernail) comparison with a standard set of surfaces machined in the same way.

Our range of Roughness Comparison Specimens can help in such cases. They are simple to use, inexpensive, and hence widely used in many different applications. The golden rule to follow, is to use comparison specimens which have been machined by the same process as the work piece being checked.


  • 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
  • estimating surface roughness prior to accurate measurement by a stylus instrument, as recommended in BS EN ISO 4288,
  • checking the seriousness of damage to parts caused by nicks, dents and scratches
  • checking reconditioned ship propeller blades




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.

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