flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 26000 single pounds per square inch shear strength anodize or chromate surface treated
3a thread class right-hand 0.497" thread length flat countersunk head style 28 thread quantity per inch two lead thread, drilled hole, 0.375 in. from top of head, 0.097 in. min. cadmium surface treated unf thread series
3a thread class right-hand 0.381" thread length hexagon head style 0.615" grip length 32 thread quantity per inch passivate surface treated unf thread series
3a thread class right-hand 0.338" thread length flat countersunk head style 32 thread quantity per inch passivate screw surface treated unjf thread series