Starrett Double Squares (13 and 13M series)

Another very popular tool that makes life easier. The key difference between a regular combination square and these double squares is that the handle is precision ground square on the blade on both sides and parallel front and back. Being small, it fits into a pocket which is a good thing. It's certainly more than accurate enough to square up machinery and fences, and it's a fine layout tool. The larger 6"" (and 150mm) size comes with a level in the handle. Like all Starrett equipment the tool has a certain solidity and feels great in the hand.
Two lengths of blade are available (4"" and 6"") in both English and metric units. The English rules are etched in easy to read 8ths, 16ths, 32nds, and 64ths. The metric rules are marked in mm on one side and in mm and 1/2 mm on the other.