flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 0.251" grip length 814 single pounds per square inch shear strength
3a thread class right-hand 1.135" grip length 28 thread quantity per inch 125000 single pounds per square inch shear strength passivate surface treated unjf thread series
3a thread class right-hand 0.669" thread length dished hexagon head style 2.303" grip length 20 thread quantity per inch cadmium surface treated unjf thread series
2a thread class right-hand 0.438" thread length flat chamfer head style 32 thread quantity per inch passivate fastener surface treated unc thread series