What is the best way to specify a countersink on a hole through a shaft?

[lroose]

I need to specify a countersink on a hole that passes through a cylindrical shaft. When fully created, the resultant shape of the outer perimeter of the countersink is an oval due to the interface with the cylindrical shaft surface. I want to ensure that the countersink is created around the entire perimeter of the hole and not only on two areas opposite each other. Any recommendations on how to specify this on the print?

[TomD.inPDX]

Typically this is defined in a section view along the long axis of the oval. there you specify the diameter and the angle.

[dschenken]

Section the hole either the long or short way on the csink and dimension the width there -or-

My favorite method, one that is not used enough, is to dimension to the theoretical sharp of the cone of the countersink, which is, regardless of the shape of the upper surface, where the theoretical sharp of the cone on the mating screw is going to be. The best part is that it directly controls the depth the tool is pushed into the metal when the csink is made, unlike the diameter, which is affected by the cone angle and the surrounding surface.

Either way, use a section and it will be clear to everyone.

[lroose]

Thanks Tom and David,

I was considering one of these methods but wasn't aware that drafting standards provided unique instruction for this situation so thought I'd ask.