These 6” and 12" rigid machinist rules feature 4R markings with 8ths and 16ths markings on one side and quick-reading 32nds and 64ths on the reverse side Photoetched graduations conform to strict international EEC 1 Accuracy Standards, i.e. +/- 0.2 mm at 20 Degrees C for 1000 mm rule Rules are made from rust-resistant, tempered Japanese stainless steel Finish is brushed stainless steel Overall size of the 6 inch rule is 3/4 inch wide by .040 inches thick. Size of the 12 inch rule is 1 inch wide by .040 inches thick. A good, quality machinist rule is an indispensable tool used by machinists, woodworkers, architects, draftsman, scientists, students, DIYers and more. When used correctly, a good steel rule is a surprisingly accurate measuring device. These rules are made from Japanese rust-resistant stainless steel that has been tempered creating a measuring tool that can flex if needed but will snap back straight. The edges and ends have been ground parallel, straight, smooth and square. Graduations are produced via a photoengraving process creating very consistent and accurate markings with uniform line widths. Once etched, graduations are black filled for easy readability. Graduation are etched and not printed so will not wear off with prolonged use. Graduations conform to strict international EEC 1 Accuracy Standards, i.e. +/- 0.2 mm at 20 Degrees C for 1000 mm Rule. 4R graduation marks feature quick-reading 32nds and 64ths on one side and 8ths and 16ths on the reverse side. Finish is brushed stainless steel. Each rule comes in vinyl storage pouch. These are well made rules and will provide years of reliable service in any shop, studio, clinic, lab, classroom or home environment.