Annular Cutter Arbor From R8 3/4" End Mill Holder

[jjr2001]

I bought this 20mm by 50mm long carbide tipped annular cutter for cutting brass round from flat.
The cutter was a steel on ebay for about 12 bucks. Nice thing about the annular cutter is the
reduced power required to drill a hole and the nice chunk of material you get instead of just chips.
Worked great just by holding it in a 3/4" r8 collet for brass. But I knew better than to try that with steel and
it should be locked into the holder for cutting any material.
Not willing to order up an arbor for the cutter I tried the fit into my r8 3/4" end mill holder.
It fit like a glove but the flats would not enter far enough to engage with the set screw.


Ok, the annular cutter has two flats at 90 degrees (not shown in the picture). It also has a ridge
that prevents it from slipping upward into the holder. The set screw in the end mill holder would
not engage the flats on the annular cutter.

That left only one thing to do. I heated it as hot as I could get it (just short of cherry red) in the
area where I wanted to drill a hole for my new "annular cutter set screw". The flat was ground on the
outside of the holder first. Just did that by hand on the bench grinder.

After it cooled, I checked and it was soft enough to drill with a HSS drill bit.

So you can see the results. A two purpose R8 arbor. Saved some money and
got my new arbor in a couple of hours instead of 5 days for shipping.

Cheers, JR