Straightedges are quality 304 stainless steel with electro-polished finish will not corrode and the precision-ground beveled edge remains straight and true after many uses. Model has no markings. Used in many ASTM and AASHTO concrete and soil test methods for trimming and leveling specimens. Dimensions are 11.81 x 1.57 x 0.125in (300 x 40 x 3.2mm), L x W x D.