"EXTERNAL SPLINES FIRST END; MAJOR DIA 3.531 IN.; MINOR DIA 3.031 IN.; SECOND END THREADED 2.8125-12 UNS 3A; THREAD EXTENDS 1.000 IN. FROM END; COUNTERBORE DIAMETER: 3.150 IN. NOMINAL; COUNTERBORE DEPTH: FIRST END, 2.470 IN. NOMINAL; SECOND END, 3.050 IN. NOMINAL"