81 PIECE GRADE AS-2/B SQUARE STEEL GAGE BLOCK SET (4101-0052)

81 Piece Grade AS-2/B Steel Gage Block Set Each block has a threaded center hole. Made of the highest quality tool steel. Surface hardness is HRC 64. Accurate to +/- 50 millionth. Complete with manufacturer's calibration or certification that is not NIST traceable. Meets or exceeds U.S. Federal specification GGG - G - 15C. Supplied in a sturdy fitted wooden case. ~ Shipping Weight: 10.8 lbs