Tapered Square metal punch anyone?

Hi, it might be useful to have a tapered square metal punch of small dimensions say starting at 1/8 inch and increasing there of. Any ideas as to their availability?

Chris

Make your own

Q Max punches do some square and round punches. They work well in aluminium but struggle a bit in steel. Once very popular for valve sockets in old electronic equipment.

Back in the days when iron was shaped with a hammer and chisel, one of the tools in the blacksmith's grubby hand would have been a square chisel, used to cut grooves across the face of the work piece before using a flat chisel to take off the lands. One such of an appropriate cross section with the end ground flat instead of oblique would serve.

Where would one buy such a thing? I guess one would make it, possibly starting with a suitably sized square file. Grind off the teeth, don't worry about over-heating it as you go, it's going to be heat treated later anyway.

Once it is to size and reasonable surface finish, stick it in the fire overnight to soften it, then heat treat it to blue as spring steel.

Robert is your father's next of kin.

Rgds Simon

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”For what purpose ?“ ... May I ask ?

Forgive me if you have some particular project in mind: but my first instinct is that it seems a good way to produce some rather undesirable ‘stress raisers’

MichaelG.

Your right Roy but just checking first. Doesnt need to be too fancy as will onlu use it on aluminium and brass.

Chris

Edited By Chris TickTock on 08/08/2020 14:25:56

It's the tapered bit that is worrying me. How does that work then?

regards Martin

Click spring over on YouTube has a video showing how:

**LINK**

Seems fairly straightforward

Dave

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That’s a broach ... Is that what Chris meant by a ‘Tapered Square metal punch’ ?

MichaelG.

Edited By Michael Gilligan on 22/08/2020 21:28:29

That video shows how to make and use a broach but Chris's question was about a tapered punch (whatever that is).

I followed the thread hoping he would clarify his requirement.

Ian P

As yet I have not made a tapered square punch,....however, it must be very similar to making a tapered winding square on the end of a clock spring winder.....

I make these by first turning the right taper on the end of the arbour, then while still in the chuck, I file a flat on the top of the taper,...then turn thru 90 degrees using a suitable change wheel on the rear spindle for accuracy, and file another flat.....i continue like this until all four flats are filed and then true up a litttle so that there is the merest trace of the original taper at the edges of the flats, and that these ARE ALL OF EQUAL WIDTH....harden and temper.

....For a punch I would make the taper/flats longer and carefully take the flats to each others edges rather than leave a smooth corner as above.....I don't think this is a particularly difficult job and a good blacksmith could do this by hammering only in about half the time that it takes me.

CLICKSPRING - interesting use of a swivelling headstock!

One of my many failings to date (which I can now see and am trying to address) is the pace of my accumulation of knowledge. By this I mean I see something interesting find out about it make notes with the intention of making it then see something else that diverts me. mostly I have made that I have intended but not in the case of the square broach or tapered square punch.

With regards to a square broach if my memory serves me i was looking into ways of making a key. The tapered punch was looking at a way i read on the clock forum of enlarging a hole for a particular function, I think for making the small 'counting' cam on the strike rack. On first thoughts using a tapered square punch sounds decidedly risky as opposed to using a file carefully. However if I remember the person advocating this was a English clock maker with a good reputation so my thinking was it is worth noting.

Thanks to all posts, as always noted. Bob 's method as stated is helpful. As my lathe and mill  Sherline I could either do the same or even use index blocks and the mill.

I am improving but as my machinery / accessories grow I have had to slow things down to make more comprehensive notes so when I go back I fully have documented all relevant detail.. All going well and

As I have said before no hurry,...it is but a pleasure.

Chris

Edited By Chris TickTock on 23/08/2020 09:48:08

When is a punch not a punch. ? When it's a broach.

Maybe a moderator would like to change the thread title so it asks the right question then.

regards Martin

Na, it's much more fun trying to interpit the originators mind. On another forum split pins are questioned, Rollpins, Selluc pins or Spirol pins are what he REALLY meant. DOH!

Regards Ian.

Going by his moniker Chris is interested in horology, maybe he would do better to ask these questions about tapered square punches and broaches etc on a horological based forum as clock makers do things totally differently to engineers, not saying they are wrong, but different. Also plenty of good books out there to help explain their different ways of working etc. The only tapered square punch I have in my shop is the tang of a round file, punches a beautiful tapered square hole into it’s wooden handle.

Sounds like a square peg in a round hole.

Chris, page 147 of George Daniels "Watchmaking" has a good description and illustrations of how to make a square broach from silver steel. He also describes how to use one.

If you haven't got it, it's a book well worth having. A lot of the information scales up for clockmaking.

I've also milled them quite quickly and easily.

As others has mentioned Youtube's "Clickspring" is a mine of information regarding things horological. Very well presented too.

Steve