This precision machinist rule is made in the USA by Products Engineering Company (PEC Tools), a premier US tool manufacturer. It is coated with Titanium Nitride for extreme scratch resistance and ultra-high contrast. It is made from the finest steel available and is hardened and tempered. Graduations are precision photo etched and then black filled for easy readability. 5R graduations show 10ths and 100ths on one side and 32nds and 64ths on the reverse Rule is .500 inches wide and .020 inches thick. Both long edges are ground flat and straight.