It is made from 1/2″ wide, C1095 close grain, high carbon spring steel. Never worry about conversion tables again with these True Metric thicknesses. Used as shim stock to fill gaps and spaces in dies and machinery; can be used for short runs or prototype work. Thickness is marked every 6″ measures 12.7mm wide by 7.6m long. Precision Brand® Feeler Gage is used in manufacturing and maintenance operations wherever setting close spacing or checking extremely tight tolerances is required.