Used on pilot house door light handle side. 2a stud thread thread class right-hand stud thread 0.500" stud thread thread length 1.437" overall length 16 stud thread thread quantity per inch end is chamfered .0468 x 45 degrees, head height-.375, head dia. .625 (5/8) material per astm-A276 typr 316, cond a unc stud thread thread series