3a thread class right-hand 0.346" thread length round w/wrench flats head style 28 thread quantity per inch passivate surface treated unf thread series
2a thread class right-hand 0.500" thread length flat countersunk head style 16 thread quantity per inch surface treatment - black oxide unc thread series
3a thread class right-hand 2.608" thread length flat chamfer head style 0.062" hole diameter 18 thread quantity per inch cadmium surface treated unc thread series
flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 0.188" grip length 1270 single pounds per square inch shear strength cadmium surface treated