Top washer has the following features:The Working Load Limit and Recommended Torque value are permanently stamped into each washer. Washer is color coded for easy identification: Red - UNC thread. Individually Proof Tested to 2-1/2"times Working Load Limit. Bolt specification is an Alloy socket head cap screw to ASTM A 574. All threads listed are UNC. BOLT SIZE IDENTIFICATION: The size of the bolt will be stated as in the drawing below. llustration shows meaning of each dimension given. NOTE: For Special Applications, see page 449. Frame 2 and larger are RFID EQUIPPED.