3a thread class right-hand 0.420" thread length flat chamfer head style 40 thread quantity per inch passivate fastener surface treated unrc thread series
flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 0.219" grip length 1980 single pounds per square inch shear strength passivate surface treated
2a thread class right-hand 0.152" thread length flat countersunk head style 56 thread quantity per inch passivate screw surface treated unc thread series
2a thread class right-hand 0.530" thread length flat countersunk head style 16 thread quantity per inch cadmium screw surface treated unc thread series