How to cut thread on bronze rod?

[outofthenorm]

Need some instruction on how to start and cut a thread onto a silicon bronze rod. I have a set of dies, but don't know how to use them for this. Utube has videos on extending threads on a bolt, but nothing on threading a rod from scratch. Can anyone post instructions or point me to a video somewhere?

- Norm

[bott]

Well, I did this pretty easily with 1/4" Si Bronze rod. I put it into a machinists vice, and slowly turned the die with a closed end wrench. I kept my other palm flat on the top pressing down flat with firm pressure. I could feel it bite and essentially "self align" on the rod, assuming its cut well and flush on top.

Hope this helps.

[Peerie Maa]

Are you talking about dies

and holders

Set the die to a shallow first cut by tightening the centre screw and backing the others out. Then run the die down again cutting deeper by slackening the centre screw and tightening the outer screws. Always use a cutting lubricant.
or die nuts


These are used for cleaning up existing threads, and can be hard to use when cutting new threads.

[StevenBauer]

Well that explains my trouble trying to thread the rudder post for my Footy last summer.


Steven

[outofthenorm]

Aha! I suspected there was something basic I didn't know. What I have are die nuts. I do not have an adjustable die or holder as pictured - which explains the difficulty I had trying to start a new thread. Gotta get the right tool for the job.

Thanks!

- Norm

[willmarsh3]

Here's my efforts to thread a bronze rod.

http://www.willmarsh3.net/el/elver041705.html

The die holder definitely helps to even out the forces applied to the die.

[jackster]

ottn,
Be sure to chamfer the rod end first.
And be sure to use the tapered, starting end first.
Also, break the chips, once you get everything square first, by backing off (back) every 1/3 to 1/2 turn. Good luck .

[paladin]

First ya buy a carton or two of American cigarettes......then ya find the local "metalsmith".....argue for one hour over a 20 minute job, come back in two days and pick up the work and leave the cigarettes......youse guys dunno how to do nuthin'.......

[Garret]

Originally Posted by outofthenorm

Aha! I suspected there was something basic I didn't know. What I have are die nuts. I do not have an adjustable die or holder as pictured - which explains the difficulty I had trying to start a new thread. Gotta get the right tool for the job.

Thanks!

- Norm

One further tip on getting the right tool. Do not buy chrome plated dies or taps. The dies (unless adjustable) make slightly undersize threads on rod, while plated taps make oversize. Put a rod tapped with a plated die into a nut made with a plated tap & it'll wobble badly & have greatly reduced strength.

[outofthenorm]

Originally Posted by paladin

First ya buy a carton or two of American cigarettes......then ya find the local "metalsmith".....argue for one hour over a 20 minute job, come back in two days and pick up the work and leave the cigarettes......youse guys dunno how to do nuthin'.......

LOL. Do they have to be American? My Dad always used Export A's eh?

- Norm

[Bob Smalser]

Don't cut your rods to finish length until after you've threaded a few.

Getting the die and resulting threads perfectly plumb takes attention and some practice freehand.

[BBSebens]

I don't know about bronze, but i've never had trouble making threads on mild steel rod using a die nut. It helps if they are sharp. I spent 15 min. trying to get a thread started, then grabbed one from a guys personal set which were almost new. piece of cake.

its all ready been said, but Ill say it again, use lots of cutting oil.

[outofthenorm]

Thanks all.

In summation.

1 Get the right tool - not chrome plated, and make sure it's sharp
2 Bevel the end of the rod
3 Use the die the right way up
4 Take care to get the die and the rod plumb - and that takes practice.
5 Use lots of cutting fluid
6 Don't forget to "back off" the cut after each advance to clear the chip

Or, just find a metal-smith who still smokes.

[Hwyl]

I agree, of course real men cut them on a lathe

[Canoez]

Then again, you can buy threaded bronze rod (plain bronze, silicon bronze etc.) from a variety of sources... Linky If you're not making scads of the stuff, it's probably cheaper to buy it than to get the stock and the tools to cut the thread.

That is, unless you want to learn how to thread parts, which is also admirable, of course.

[AstoriaDave]

I've cut threads on 3/8ths SiBr bolts and similar stock. You definitely want a sharp die. SiBr is soft enough it does not chip out as well as steel. But, if you work away at it, it is easy.

[seafox]

The other week I cut threads on a 1 inch shaft with the type of die pictured above and it was chome nuts seem to fit fine. it toof a couple of hours before I was first able to get it going. used cutting oil and a crecent wrench ( adjustable spanner for out brit friends) was extra carefull, wish I had had a box end wrench would cut 1 / 12th of a turn forward then back off 3/8ths to clear the chip and keep from breaking die. over all it took about 6 man hours on two different days to finish three inches. and you know I'm a batchlor because I cut the threads in the kitchen so the dogs could track the metal cuttings through out the house
jeff

[TimH]

Originally Posted by Hwyl

I agree, of course real men cut them on a lathe

Or take to a local machine shop and give a guy $20 to do it on his lunch break

[Nicholas Carey]

Originally Posted by Bob Smalser

Don't cut your rods to finish length until after you've threaded a few.

Getting the die and resulting threads perfectly plumb takes attention and some practice freehand.

If the rod isn't too long, using a drill press works pretty well for getting things started plumb:

0. Unplug drill press. We do not want power assist with this operation.
1. lower drill press table. Ensure that it is square to chuck axis.
2. clamp die into machinist's vice on drill press table.
3. chuck rod into drill press.
4. raise table until die is convenient to end of rod
5. Lower quill so rod contacts die with enough pressure.
6. Rotate chuck manually. Might want to put a strap wrench on the chuck to give you some purchase.

Works pretty well. Once could probably jig something up, but the drill press was convenient.

[Canoeyawl]

There are die holders available with pilots to square and center the die.

(edit) -this is an inexpensive one for small stuff, up to 1/2"
Irwin

If you have quite a few to do, it is a good lifetime tool investment.
this is one type used for bolt threads to 1 inch - Ridgid Tool Co.