PEC Tools Rigid 6" 5R Titanium Nitride (TiN) Coated Extreme Scratch Resistant Ultra High Contrast Machinist Engineer Ruler Scale with Markings 1/10, 1/100, 1/32 & 1/64 502-006TN 6" 5R machinist ruler is Titanium Nitride coated for extreme scratch resistance and ultra-high contrast 100% made in the USA by Products Engineering Company (PEC Tools), a premier US tool manufacturer It is made from the finest hardened and tempered steel 5R graduations are precision photos etched and show 10ths and 100ths on one side and 32nds and 64ths on the reverse Rigid rule is .750" wide and .035" thick. Both long edges are ground flat and straight