Steel carbon qq-s-633, one end drill1/2 in. Diameter hole 3.550 in. Deep, counter drill 1.125 in. Diameter 1.500 in deep, counter drill 30 degrees seat, from same end 3.340 in. Deep drill 2 holes 0.375 in. Diameter thru, o/a dim. 1.373 in. Diameter by 4.120 in. Lg