2a thread class right-hand 1.126" thread length hexagon head style 20 thread quantity per inch fastener end csk. 0.215 in. dia. porm 0.005 in. x 120 deg.; locking feature is 0.1875 in. dia. porm 0.001 in. x 0.435in. deep porm 0.005 in., located 0.470 in. porm 0.030 in. from fastener end passivate fastener surface treated unf thread series