6" Spring-Tempered Steel Rule - Inch Graduations, Aircraft Quick-Reading 50ths one side & Quick-Reading 10ths on other. The Starrett 6" Spring-Tempered Steel Rule with Inch Graduation features a satin chrome finish. Graduations at both sides including aircraft quick-reading 50ths (.02) on both edges, one side, quick-reading 10ths (.10) on both edges,opposite side. 6", 6R Grad side.