2a thread class right-hand 0.984" thread length 2.500" overall length 16 thread quantity per inch furnished with nut zinc surface treated round, open unc thread series
3a thread class right-hand 1.660" thread length 4.000" overall length 18 thread quantity per inch groove in base 0.093 in. radius by 0.040 in. deep round, closed unjf thread series