Used on tf-33 engine;engine a/c,tf-33-100 (e3a/b/c);engine aircraft, tf-33-p-7;aircraft,c-18a,ec-18b;aircraft,stratofortress b-52;aircraft,stratolifter c-135;aircraft,f-111 (fms only). 3a thread class right-hand 0.488" thread length 28 thread quantity per inch unf thread series
2a thread class right-hand 0.851" thread length flat chamfer head style 20 thread quantity per inch 1/16 in. by 3/32 in. taper end of knurl unf thread series
