Used on 4austin ship class lpd-4 amphibious transport docks, tarawa class lha, nimtz class cvn, virginia class cgn (41), whidbey island class lsd, forrestal class cv, supply class aoe, oliver perry class ffg, safeguard class ars, spruance class dd (963). 2b thread class right-hand 1.400" overall length 0.440" overall width 40 thread quantity per inch weapon system essential unc thread series