Thread: L plater looking to cut unf on stainless rod. Input??

Personally I wouldn't be doing it under power at all but swinging the chuck by hand with the power off. Others may do it differently.
You don't say whether the dies are carbon steel or HSS, you may find stainless to be a bit of a challenge with carbon steel dies. If at all possible I'd consider making most of the thread by single pointing with the lathe and then finishing off with the die.
Use of a cutting oil like RTD or Tap-Magic will help.

Unless you have a Coventry head or similar, threading with normal dies (under power) is not normally recommended. You may use the tailstock to help line things up though.
Regardless, if you are threading stainless, I'd recommend Trefolex to help.

Michael

As far as I know you don't die cut under power ,so the rpm will be zero.

I cut with my dies by winding over the chuck by hand.I use this method to get alignment of the die on the shaft.
A tap, particularly a spiral machine tap is different matter all together.

If I am talking out my backside, I expect a machinist will come along, shortly, and tell you different.

As I understand it, threads are other wise cut by a single point tool under power.

Grahame

Do you know that you can buy rod already threaded.It is called allthread. I am fairly sure you can get it in UNF .

Try a fastener shop, ie bolts and nuts

Slow.

Is this tailstock die holder adjustable,can you close it up or release it to allow the die to cut oversize and sneak up on your finished size?

Whats the end job to be used for?

If the finished thread size is not critical turn a few thou off the OD to allow the die not to be worked to hard,also put a decent chamfer on the end of your shaft.

Originally Posted by Grahame Collins

Do you know that you can buy rod already threaded.It is called allthread. I am fairly sure you can get it in UNF .

Try a fastener shop, ie bolts and nuts

That is exactly what I'd do. Cutting threads on a 316 or 304 rod with a die is not going to be productive. Been there, done that, blunted lots of dies.

Ditto single pointing the threads. Cutting long thread lengths on s slender shaft is also a PITA. Better have a good and well fitting follow rest.

Not that it can't be done, just better avoided if possible.

My standard trick these days is to weld some stainless allthread onto a stainless shaft if I need a long bolt or similar.

PDW

Originally Posted by pipeclay

Slow.

Is this tailstock die holder adjustable,can you close it up or release it to allow the die to cut oversize and sneak up on your finished size?

On stainless? It will most likely work harden if that is done...

Can you get SS allthread with imperial threads? I tried the other day and could only find metric. Admittedly I didn't try very hard!

Originally Posted by Grahame Collins

Do you know that you can buy rod already threaded.It is called allthread. I am fairly sure you can get it in UNF .

Try a fastener shop, ie bolts and nuts

As above. Also, the all thread will be a rolled thread so it will be stronger than a cut thread (assuming same or similar grade of material)

bollie7

Originally Posted by jack620

Can you get SS allthread with imperial threads? I tried the other day and could only find metric. Admittedly I didn't try very hard!

Sure can.

UNF in 316 here.

http://www.austain.com.au/shop/listi.../threaded-rod/

UNF in 304 here.

https://www.bolt.com.au/stainless-st...1588_1780.html

Not exactly cheap, but by the time you've stuffed a couple of dies, and got one or two jammed, I'd say its well worth the price. I'm sure it could be found cheaper fairly easily too.

I'll avoid having to tap or die stainless wherever possible, its just painful. If I can't, I'd prefer single pointing with carbide, but as PDW said - on that size stock? Wouldn't even bother...

Maybe wrong, but I was assuming the OP just wanted to thread the first 1/2" of the rod.

G'day Peter,
My suggestion would be to single point your threads nearly to size and then finish them off with a die rather than trying to use the die from scratch. 304 is easier to thread than 316 and is less inclined to tear. You don't need a steady if you're only cutting 1/2" long threads, just keep the work as close to the chuck as possible. For fine threads forget about carbide, use a nice sharp HSS tool and a good cutting compound (Trefolex CDT or Rocol RTD). As for speed, go with whatever you're comfortable with working close to the chuck, probably less than 100rpm would be best. If you aren't comfortable working close to the chuck, centre drill your rod and use a centre in the tail stock, then you can have it as far out as you like. If you don't want the centre hole in the finished job just cut your material and threads a bit longer and machine them off later. Good luck with it.
Cheers,
Greg.

Originally Posted by befuddled

Hi all,
I have purchased some 5/16" and 3/8" rod that I need to thread unf.

I also purchased new P&N dies that fit into a tail stock die holder.

So can anyone give me a recommendation on rpm speed? (Assuming the tail stock will not be tightly clamped and will follow onto the rod about 1/2" for my thread)

I have looked up cutting feed and revolution but Im still quite unclear as to the ideal given I wont actually be using 'feed' as such.

Cheers, Peter

Peter
If you are going to manual cut (Ie: turning the chuck over by hand) it will be no big deal for 1/2" or so. In fact as a new comer to this you will fare better doing a manual cut. I checked on U tube and while people do cut under power with this system but they seem to be very experienced. No "setting" of the machine is required for a unpowered cut.

What I would be making sure of :

• Switch the lathe OFF
• That the die is a HSS - it will be marked as HSS ,if so.If not it is probably a carbon alloy and will blunt real quickly on stainless
• that the die is seated square in the die holder and facing the right way - meaning that the taper side of the die is presented to the rod end .
• that the the rod has a small chamfer on the end to allow the die to taper on to the end of the rod
• that you use plenty of the correct type of lube.

Obviously, the tailstock is left free enough to be "dragged" along the ways by virtue of the thread winding in, the die /tailstock assembly inwards as the chuck is manually rotated.

The tailstock die holder should also have a handle which can slide over the top of the ways, saddle, or compound slide - it depends on your lathe and tailstock die holder on where the handle will sit on to slide.

It is important that this handle can slide un-impeded for the length of the thread to be cut.

This handle prevents the tailstock die holder from rotating with the rod to be threaded but it must have longitudinal movement for the length of the die cut thread.

Hope this helps

Grahame

Originally Posted by Grahame Collins

Obviously, the tailstock is left free enough to be "dragged" along the ways by virtue of the thread winding in, the die /tailstock assembly inwards as the chuck is manually rotated.

My tailstock die holder slides along its own shaft/arbor/thingy, allowing me to lock the tailstock in place. The attached picture isn't mine, but it's that style.