Combination Square Set (490 Series)

Combination square set. Center head (made of cast iron): to locate the center of a cylinder with diameter (d) 1.181'' DIA-3.937'' DIA, accuracy ±.006''. Protractor head (made of cast iron): sets the blade at the desired angle to an edge of a workpiece, measures angles range 0-180°, accuracy ±20 min. Square head (made of cast iron): sets the blade at 90° or 45° to an edge of a workpiece, accuracy ±8 min for the 90° square, ±10 min for the 45° square. Blades are hardened and tempered for durability. The square head has a level and pointed attachment for hand scribing. Micro-fine blade graduations. Gauge heads are hardened cast finished in baked enamel with the exception of the measurement faces.