What tool do I need?

[nvrenuf]

I bought a used hd diff cover a while back and just noticed that the bolt holes must be designed for allen head bolts, there’s no room for a bolt’s hex head between the hole and the “belly” of the cover.

Is there a tool / bit I can use in a drill press that I can use to cut into the belly to create a seat for the hex head? It would be cutting on the edge and side rather than the flat surface directly under the bit.

Something with a hole size pilot would be really helpful.

 

[76zimmer]

I’m thinking something like this?

Counterbores - For Cap Screws - - No.6 HSS 3F Solid Pilot Counterbore

www.msdiscounttool.com

 

[nvrenuf]

I’m thinking something like this?

Counterbores - For Cap Screws - - No.6 HSS 3F Solid Pilot Counterbore

www.msdiscounttool.com

Oh yeah, that’s got to be it. Thanks!

 

[kennyw]

It would be easier to use 12 point heads.

 

[nvrenuf]

It would be easier to use 12 point heads.

View attachment 536333

That’s a good idea and they would have a smaller footprint than a hex head but I’m not sure there’s room for that flange. I’ll take a couple of pics tonight, the ramp of the bowl is right on some of the holes.

 

[kennyw]

That’s a good idea and they would have a smaller footprint than a hex head but I’m not sure there’s room for that flange. I’ll take a couple of pics tonight, the ramp of the bowl is right on some of the holes.

The diameter of the 12 point head is typically about the same as the socket head but they are much harder to round off than the internal Allan. I grabbed 3/8-16 ax 1/2" lg for example dims, but you can look up dimensions of what you need on McMaster fairly easy.

 

[nvrenuf]

@kennyw thanks, that’s good stuff! I would have bet money the 6pt vs 12pt bolt flanges would have been similar diameters.