PDPAWL Drive Pins with 1" Washer - Includes 1" preinstalled Washer. For Structural Steel and Extra Hard Concrete - For A36 and A572 Grade 50 structural steel (red strip load recommended). 0.157" diameter for greater compressive strength. Manufactured with tight tolerances for superior performance. For Simpson Strong-Tie Powder-Actuated Tools - PTP-27L, PTP-27S, PT-27, PT-22P, PT-22, PT-22GS, PT-22H. Also Compatible with 721, D-60, U-2000, System1, System 3 and other low velocity tools.