Die nut

Can die nuts be used to form a thread on steel bar? I remember reading somewhere that they are designed to touch up existing threads. Nut in question would be 1 1/4" BSW.

In a word ... No

[now waiting for somebody to prove me wrong]

MichaelG.

As Michael says, even if it were a split die you would probably rip your vice off the bench trying to turn it round with a 4ft scaffold pole on the end of the diestock. Really only for cleaning up existing or final chasing of a partly screwcut thread.

Edited By JasonB on 09/07/2016 15:22:19

Well, i haven't seen a BSW one but i've found dies online that will go larger than an inch, but i haven't ever cut one that big before, biggest i've got is M16. that was using a 2" stock. 

Michael W

Edited By Michael Walters on 09/07/2016 15:32:49

Here yer go; die on the left is 1-1/4" BSW, the other is 1-1/2" BSF, both 3" diameter:

Andrew

Michael & Andrew ... I'm a little confused

How do your replies relate to the original question ?

MichaelG.

I believe Micheal was replying to Jason who thought that a die for such a large diameter might not exist/ be practical then Andrew was replying to Micheal saying he had never seen a BSW

Thanks ... I will just get back in my corner.

MichaelG.

Well the split nut clearly shows it could be cut. So the answer is yes, i reckon you could do it. Hasn't anyone seen the sort of dies used for pipe threading before, they're huge. (Now those are probably just for cleaning/repair) But i don't think a 1" Dia. thread with a coarse pitch is too big a push in 2 passes. 

Michael W

Edited By Michael Walters on 09/07/2016 17:14:54

Pipe threads of a similar diameter are a much finer tpi so you are removing about 26% the metal you would with a 1.25 x 7tpi whit dienut.

The other advantage when using pipe cutting dies is that they have a lead in guide as part of the die. They are made to cut threads not clean & repair. I use this one quite often but even with something fairly small like 3/4 " BSP (just over 1" OD) it takes a lot of effort. This one is being used for 3/8" BSP on a model.

Also worth remembering that Rainbows wants to use this as a lathe spindle so got to be nice and true. It was the practicalitioes of using a big die that I was pointing out not querying their existance. Michael W just becasues split dies exist doies not mean they will easily cut from scratch, they can be used to chase as screwcut thread and fine tue the fit whereas a diesnut can't be fine tuned.

The other proplem with cutting big coarse threads is physically holding the part, you really need a pipe vice with its serated V jaws as a chuck or bench vice will be hard to do up tight enough.

Edited By JasonB on 09/07/2016 18:29:10

I tried a 1" die when making some keel bolts, no luck at all! I screwcut the threads and finished them with the die. I suppose a guided die may work if you have to do it this way. I've cut hundreds of 25mm conduit threads by hand, it's a bit tiring if you spend a day doing this. The spec of the steel may be the decider.

Michael W The original question was regarding the use of a die nut

Die but is strictly for cleaning up existing threads. For up to 2 inch diameter BSW taps and dies Tracy Tools have them in stock. HTH.

That should read "die nut" of course. Link to TT is on this page as one of ou "Shopping Partners"

At work we occasionally have to cut BSP threads for 4" pipe etc, this is done with an electric pipe thread cutter and it certainly makes the machine grunt cutting the thread.

Martin P

Tracytools only go up to 1" for BSW as far as I can tell?

.

Available here, if you must

... But I would really advise against trying.

MichaelG.

You know, i've got a pipe vice and it's been a dust collector for ages, i bought it thinking i'd use it to cut up alot of bar and now i just part off or use the bandsaw and i really wondered why i got it, i asked my mate who's a farmer if he wanted it for the yard, and he said he's also got one and can't think of what to do with it!(he also referred to it as a "pipe bender" rather than a vice)

 So now i know what i can use it for. I literally couldn't give the thing away. damn.

Michael W

Edited By Michael Walters on 09/07/2016 20:18:52

This for your mandrel nose, I guess?

I would screwcut it, there's no way a die that size will cut a spot on thread straight off. You CAN use a die nut to finish the screwcut thread.

Neil

Well my guess is steel bar could be anything, hence why i thought i was being relevant.

Michael W