2b single mounting facility thread class 4.000" overall length 1.310" overall width 32 single mounting facility thread quantity per inch unc single mounting facility thread series
2a single mounting facility thread class 0.375" single mounting facility thread length 1.561" overall length 1.188" overall width circular wafer, bushing mount unef single mounting facility thread series
Used on aircraft, f-15. 2a thread class right-hand 1.093" overall length 32 thread quantity per inch mounting bushing thread on back of item. weapon system essential unef thread series