I have an application where I need to make some small stainless steel core pins for a mold. I have some .090 spring wire that would probably work fairly well after I straighten it. Straightness does not have to be perfect, so I'll probably just do that part by hand. Then I run into my issue. I need to taper it from .090" down to about .070" over a reach of about 1.25 inches.
The only thing I could think of is to to a shallow v block and clamp that it the tool holder on the mini lathe. Then lay a file against one end of the V block and slowly bring it back until its just scuffing the wire at the 1.25 inch mark. The grove is to hold the wire from bending against the cutting force of the file. My concern is if I will be able to continue to cut the wire with the file as it work hardens from the action of the file. My other concerns are that I have my hands so close to the spinning lathe, and that this seems to be a very hand skilled approach to the problem.
No the pre tapered pins for sale from McMaster absolutely WILL NOT work for this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.I guess its time to go play with a file and see....