Making HSS form tools

I posted this as an idle query in another thread, but since it threatened to derail the thread I thought I'd better split it out. My original query:

> While we're on the subject, can I ask about filing HSS? I'm interested in making form tools - I know I can heat treat O1 or the like but I'd like to avoid the extra faff. I imagine diamond needle files are the way to go here but I'd like to get one decent set that will last.

The reason I'm thinking diamond files is the shapes I need to create are quite small and while a grinder could do some of the work, I'm thinking of things like this:

The blanks were drawn at 5mm (vertical) across, and most would be in this range. The notch in the bottom one is about 1mm wide and deep.

surely it must be easier to form your shapes in 01 then harden and polish and then temper?

Calum, I wouldn't fancy filing those shapes in hardened HSS, by all means have a go & report back. What would the tools be producing?

Tony

I know you said you’d rather not use O1 but I’ve found it really easy to harden. In many instances I’ve not bothered tempering it and not had anything break so far.

Dremel with grinding discs will do it. I do my gash when sharpening end mills with a diamond cutting disc on a Dremel.

I think I would be hard pushed to get the crisp internal corners of the last one with my Dremel or even a file or T&CG, not a problem to mill gauge plate though.

Are they for decorative rings on your pipes and if so what material will you be cutting with them

Edited By JasonB on 27/05/2022 20:29:14

In a rash moment I bid a small amount for a rather beat up Bergeon bracelet cutting machine, Type 5683, on ebay, and as nobody else bid I ended up with something I did not really need.

I have found it very useful however for cutting HSS toolbits to length and rough shaping the ends to make lathe tools before finishing on the T and C grinder.

The machine is like a tiny cut off saw ( lots of images on Google) and uses 65mm diameter abrasive discs,( I can't remember the thickness and I am not near the workshop, but I think it's less than 1 mm ) It is powered by a tiny sewing machine type motor. Now a new machine is horrendously expensive but it would not be expensive to buy a disc and make up a mandrel to hold the disc in a lathe chuck and hold the HSS blank in the tool holder. Discs are available from Walsh's and Cousins etc.

Rod

Commercially the shapes would be cut on a wire EDM. It is possible to mill HSS with carbide cutters, although some filing would be needed for the sharp internal corner on a curve. Diamond files work well, but they are finishing tools, not for bulk material removal. Heating treating O1 is a darn sight less faff than filing shapes in HSS.

Andrew

Calum,

It may be worth you looking at the P.P. Thornton website

Their [wonderful] horological cutters are made from HSS … turned using carbide form-tools.

You never know: they might give you some guidance if you ask nicely.

MichaelG.

.

https://ppthornton.com/contact-us/

Edited By Michael Gilligan on 27/05/2022 21:57:47

Spot on! Yes, decorative (and protective) mounts, which are usually nowadays plastic or resin, sometimes wood, formerly ivory, catalin (a relative of bakelite), casein (milk!) or celluloid.

Really, any tool steel would probably be fine without heat treatment - I use untreated silver steel for long hole boring in wood and delrin and have no trouble with it. But I'd like to ultimately get to the point where I'm able to bang stuff out quite quickly, and wood can be surprisingly hard on tools.

Credit : https://watchmaking.weebly.com/uploads/1/1/7/9/1179986/pp_thornton_information.pdf

MichaelG.

Calum if you are hoping to bang the stuff out quite quickly you may be well advised to use tungsten carbide tipped tooling.