Description Warranty Information Rockwell T Scale Test Block, Actual block value will normally fall within +/- 2.5 points of the nominal value indicated in part number. - Meets ASTM E18 - Includes nominal face value with tolerance and serial number etched on block - Dimensions 0.250 x 2 x 2, 0.3 Lbs. each. W=Calibrated using a tungsten carbide ballNewage Testing Instruments offers a full line of Rockwell, Brinell and Microhardness calibration standard test blocks. All blocks conform to all applicable ASTM specifications and each serialized block comes with a matching calibration certificate. Specify desired scale and hardness range for each block ordered. This Product comes with a 3 years Warranty