heat treat to rc 55-60 per mil-h-6875; surface treat black chrome per mil-p-14538; undercut provided 0.060 wide located 0.340 from flance; counterbored 0.500-20 unf-2b, 0.190 deep passivate surface treated blind
2a thread class right-hand 0.150" thread length knurled no. 1 head style 20 thread quantity per inch undercut head 0.100 wide x 0.430 dia anodize surface treated unf thread series
Used on propeller blade aboard 210 ft "a" class coast guard vessels. 2a thread class right-hand 2.187" thread length hexagon extended washer head style 8 thread quantity per inch un thread series
3a nut thread thread class right-hand nut thread 0.370" stud thread thread length 1.255" overall length 32 nut thread thread quantity per inch furnished with one o-ring; countersunk on shoulder 0.080 in.min, 0.082 in. max lg shouldered unjf nut thread thread series
3a thread class right-hand 0.400" thread length dished hexagon head style 1.428" grip length 28 thread quantity per inch cadmium surface treated unjf thread series
