steel 1015 to 1025;cadmium plated;4.000 dia;0.375 thk;central hole 2.125/2.130 dia counterbored 2.835/2.840 dia x 0.0625 deep;2 holes 180 deg apart0.265 dia counterbored 0.390 x 0.250/0.266 deep,on 3.438 bolt circle;2 holes0.265 dia counterbored 0.390 x 0.109/0.125 deep 180 deg apart 3.375 c-to-c on line 0.312 from perpendicular axis general characteristics item description