Clear .625" (15.8mm) thick, acrylic plates used to strike off surface of unit weight measure samples. Use a plate that is 2" (50.8mm) larger than the diameter of the unit weight measure. Use 2" larger plate than the diameter of the unit weight measure. The Strike-off Plates for Unit Weight Measures supports the following standards: ASTM C29, ASTM C138, ASTM C192, AASHTO T19, AASHTO T121, AASHTO T158