Steel, astm a108; 10.812 in. Lg; with 2.000 in. Diameter shaft; end of shaft has 1-1/2-12 unf 3a thd; 1.250 in. Thd lg; 4-3/4-12 un 3a thd on head end; 1.500 in. Thd lg; 4.250 in. Hub lg; w/three 1/2-20 unf 2b thd holes in end of hub equally spaced on 2.375 in diameter bolt circle