Used on sikorsky cargo transport helicopter, ch54a andch-54b. 3a 3rd end bulkhead thread class passivate surface treated unjf 3rd end bulkhead thread series
2a 1st end thread class 20 1st end thread quantity per inch supports clark model 290m; tractor, wheeled, ind., diesel driven; med dbp, nsn 2420000889384, w/rops nsn 2420010590090 nptf 2nd end thread series
3a all ends thread class 12 3rd end thread quantity per inch furnished with 2 wig-o-flex flexible nuts anodize surface treated un 3rd end thread series
3b all ends thread class 2.312 in.dia by 0.188 in.thd flange w/four 0.220 in.min/0.226 in.max dia holes equally spaced on 1.875 in.dia bolt circle, located 0.312 in.from end passivate inside surface treated plain unjf all ends thread series
