Special Features:

Triangular layout type; for use as rafter square, for roof and stair layouts, etc.; 12 in. Lg

Properties:

A measuring tool consisting of a metal body (long leg) and a tongue (short leg) forming a 90 degree (1.6 radians) angle. Both the body and the tongue may be of the same thickness or may be tapered from the apex to the end of each leg. The item is graduated either on both edges or the outside edges only. May be inscribed with one or more reference tables and if without reference tables, the item is graduated in increments no smaller than 1/32 inch (0.8 mm).