3steel; 3.380 in. O/a lg; top portion 2.062 in. Od, internally thd 1.750 in.-12un rh thd size, 1.125 in. Thd lg; center portion 2.062 in. Diameter flatted on two sides to 1.687 in.; bottom portion 1.250 in. Id, externally thd 1.750 in.-12un rh thd size