Bevel Mechanics Protractor

A measuring instrument commonly used in the machinist trade for setting or checking bevels, transferring angles, checking cutter clearance, laying out angles and scribing lines. Consists of a rotatable disk, graduated in degrees, mounted on a metal frame base, and an adjustable steel blade or scale which is locked in position by a thumb nut, or clamped by an eccentric stud. May also be equipped with one or two small auxiliary vernier scales which enable a more accurate reading. Excludes protractor, one arm; protractor, two arm; protractor, three arm.