What are these?

They look like some kind of D-bit reamers. There are many uses for these, so it may be hard to nail down their original purpose. My guess is they were used for making brass musical instruments.

They are not commercial clock reamers, which are tapered.

Drill bits?

D-bit drills are ground at an angle on the end, unless they're made to follow a pre-drilled hole. D-bit reamers look almost the same but they're usually pointed at the end, or tapered, like a clock reamer, or else they're just left square on the end if they're just kissing the hole by a tenth or two. The reamer design I've used a lot is ground to a long taper but all from one side. They begin by cutting and finish by burnishing the hole.

They're interesting tools. You can even make milling cutters that way (the old British hobby machining books covered them pretty thoroughly). I used to make a lot of them out of broken and worn-out drill bits when I started machining as a hobby, because my teacher started his machining in the 1920s and thought everyone should know about D-bits first. I don't do much with them anymore but they have saved me a lot of grief, not to mention money, back when I was doing a lot of hobby work.

Steve B Inscribed thus:

"D" reamer's !

That tells me a lot. Could you expound your answer?

Steve

Unfinished engraving bits. D-bits for sure, D-shaped looking at the end. Can be ground to cut a V-shaped path, or more or less any shape, including that shown. Relief on the trailing side is wise.

google, maybe, engraving.cutters, d.bits, etc.

I'd buy a few from you. ?? /mark

I'll bring them in from the shop, and see what I have, and get back to you. What are they worth? Shipping should be cheap.

Steve

"Steve B" wrote

Back from the shop ................

Morse USA HS on the sides. Some with 9 4 56 (example) .098 (on one, not all)

These are very small diameter tools. Some finer than angel hair pasta.

Can anyone use these?

Steve

they look like engraving tools.

John