During the initial manufacturing process of any component the surface of the piece is measured for a texture value; this value is defined as the surface roughness (Ra) value. Today, most surface roughness values are set by industries and followed carefully by manufacturers and processors. Washington Mills’ aluminum oxide blasting grit, BLASTITE®, is used to create a particular surface roughness based on a few variables such as; the grit size used on the piece, the PSI, the distance to the work piece and the type of blast used in your process such as direct pressure or suction blast.

Surface preparation is an essential part in preparing a metal for finishing because the performance of the final coating very much depends on how well the surface was prepared. In the photo below, you will see a variety of abrasive grit sizes across the top of the photo, the kind of finish the grit sizes create on a piece of stainless steel and their corresponding surface roughness values. This guide will help you understand the type of surface roughness value achieved when using different grit sizes of BLASTITE® aluminum oxide for surface preparation on stainless steel.