3a thread class right-hand 0.250" thread length double hexagon extended washer head style 28 thread quantity per inch cadmium surface treated unf thread series
3a thread class right-hand 1.361" thread length flat extended washer head style 20 thread quantity per inch 2 holes in waser directly opposite each other 0.122-0.128 in. dia; top of head chamfered 15.0 deg x 0.380 in. passivate surface treated unf thread series
3a thread class right-hand 0.365" thread length hexagon head style 28 thread quantity per inch hardness rating 35.0 min. passivate fastener surface treated unf thread series
3a thread class right-hand 0.865" thread length double hexagon extended washer head style 0.190" grip length 24 thread quantity per inch unjf thread series
3a thread class right-hand 0.425" thread length oval countersunk head style 0.365" grip length 28 thread quantity per inch passivate surface treated unjf thread series