The PDPA is a hardened-steel, powder-actuated fastener designed to fasten building components to concrete, steel and CMU. The PDPA consists of a fastener with a 0.300-in. diameter head and a 0.157-in. diameter shank. The PDPA provides maximum jobsite productivity with fast installation. PDPA .157 in. x 1/2 in. Powder-Actuated Knurled Drive Pin (100-Qty) (Pack of 1000).