Can anyone identify this cutter?

[DavoDavo]

Hi all,
I brought this cutter with me when I emigrated from England to Australia in 1972. It has been lovingly kept in my toolbox with all the other tools since then but the other day I took it out to have a good look at it after discovering it lurking there.
I have no idea what it is or where I got it from.
It appears to be a 5/8" fine Whitworth thread pitch and is marked 5/8" however the tooth profile is near enough 90 degrees?
The shank is plain with no taper.
Thanks,
Davo.

[Technical Ted]

I have some boring bars that are shaped somewhat similar to that. Could that be a long reach chamfer tool?

Ted

[DavoDavo]

That's possible I guess, but why does it seem to have a screw cutting helix of about 2/3 of a complete circle?

[John Evans]

That's possible I guess, but why does it seem to have a screw cutting helix of about 2/3 of a complete circle?

Because to sharpen it you only need to grind the flat top surface,the other clearance angles are built in. See the old Armstrong threading cutters used mostly with the rocker style tool post system. that cutter looks like a snail shell in profile. Your tool is a boring bar, I have some similar.

[Harold_V]

It's just a (Bokum) boring bar (for mill use).

H

[DavoDavo]

Thanks for the help.
I checked out Bokum boring bars on the web. It's a through hole boring bar.

Cheers,
Dave.