Surface Roughness Conversion Chart for Deep Hole Drilling
Why Surface Roughness Units Matter In my years of deep hole drilling, I have seen countless specification sheets where the customer calls out surface finish in a unit the shop floor does not use regularly. European prints often specify Rz, aerospace jobs use RMS from the old MIL standards, and medical device prints stick with Ra. If you convert wrong, you scrap parts. I keep this conversion chart posted in the inspection area for quick reference. The conversions here are based on the ISO 1302 standard and verified against actual profilometer readings on gun-drilled and BTA-drilled bores. ...