Their versatility and reliable accuracy makes Starrett squares indespensable in any shop. Hardened & tempered satin chrome blades are graduated in 64ths & 32nds on one side, 16ths & 8ths on the other. They can read cutter height on saws, shapers and router tables, check mortise or rabbet depth, or help scribe layout lines at precise widths along a workpiece. Blades can be reversed to read whichever scale is most convenient for a given job. The 12" Combination Square offers the same level of dependability with the great convenience of 10" usable blade length for layout and checking cutoff accuracy. Heads are precision-milled cast iron with black wrinkle finish. Optional accessories convert the 12" square into a center finder for round or square stock (item 061522), or into a large precise 180° satin chrome reversible protractor (item 061523) for determining or laying out uncommon angles. Also available, a 24" Blade (item 061524) gives you Starrett accuracy on stock up to 22" wide.