3a thread class right-hand flush countersunk head style 0.620" grip length 32 thread quantity per inch black on thread end aluminum alloy surface treated unjf thread series
flush (flat) countersunk (included angle - less than 135 deg w or w/o chamfer) head style 0.344" grip length 0.016 oversize shank for repair work only. mechaincal lock passivate surface treated
3a thread class right-hand flush countersunk head style 0.193" grip length grit blast of top of head 1/64" oversized (for repair work only) . unjf thread series