I was scrounging through one of my many machinist chests yesterday looking for some small drill bits I'd seen awhile ago (still haven't found them) and ran across a metal tin full of miniature reamers and cutting tools with tapered shanks. In 50 years of machining/tool making I've never seen anything that would accept these bits. Measuring the diameters it occurred to me that they might fit a tool for clock repair. The reamers are around the sizes of pivot holes and the ball nosed cutter looks like it'd make oil wells. Maybe these fit a watchmakers lathe?
A little research tells me that nearly all watchmakers lathes have different tapers by brand and sometimes different tapers within a brand. So the only way I can make use of these bits is to make an adapter that matches their specific taper.
You are right about the different tapers for different brands, but I don't think they were actually for watchmakers lathe tailstocks. They seem to be milling cutters. Take the cutters on the top left for instance: there is no way to cut with them in the tailstock of the lathe, as there would be only an axial movment, but you need a tangential movement to cut with them. I have the feeling that they belong to an engraving machine of some sort, which used such tapers in the spindles. Wish they were mine ... I probably have suitable tapered collet for my watchmakers milling machine ...
Top left corner has 3 dovetail cutters, definately milling. The ball mill next to them is a center cutting 3 flute, could be used in a mill or lathe. The majority of the rest are only reamers based on the cutting geometry of the flutes, most are around .030" OD. You might get some cutting action out of the larger ones maybe. I didn't look at the chamfer tools close enough to see if there was back relief behind the cutting edge for mill work. I'm in the process of trying to make my own d-reamers on my Deckel SO grinder. It is very possible that the set might have come from an engraver setup, the tool box belonged to a guy that ran the R&D department of the first machine shop I worked at. They had an elaborate engraver setup in the room. I have a buddy that worked in R&D and another that ran an engraver for the company at one of our other plants. I'll ask them if they can identify them. They were all together in an old tin about the size of a Sucrets tin.
Making an adaptor is an effective method probably requiring the least amount of time. However, if the rear of the shanks happen to have a centers, a straight section on the arbor is easily turned to a desired diameter using ceramic tooling allowing use on whatever. The following shank was reduced from 3/8" to 1/4" allowing use in a 1/4" collet in my small Mill. Ceramic tooling is designed to machine hardened steel without annealing. Jerry Kieffer
Each tool holder is designed for a particular type or style of insert. You would need to identify that type or style and contact a supplier for what is needed. You would also need to identify the style of insert desired. The following example link will give some idea of what you have to choose from. insert_ceramics_index.html Jerry Kieffer
