Methods for producting straight threads?

[Bented]

Don't know other then holding the tap or die square to the parts.
Automatic screw machines have produced threads this way for 150 years.

[boslab]

Would have thought a small lathe quite satisfactory for the threads on a silencer or suppression dodah, I wouldn’t cut a 3” whitworth or BSF on one but how bigs the gun!, instrument makers have been striking and chasing threads since the start of the industrial revolution, maudsleys original lathe had a hand made leadscrew, I dint subscribe to the drunken thread theory myself, ok you can with a die nut or solid die but several passes with a split die that’s accurate and sharp, a blunt die with a inaccurate pitch maybe, buy a quality die, make sure the face of the tailstock spindle is square or perpendicular to the axis of the machine, important, easy to check by slapping a parallel on the face and clocking along it, error will show easily, check horizontal and vertical, sweep the face of the tailstock, and check tail alignment to if using a rigid dieholder, if floating not so much.
live cut threads for microscopes and cameras on the cheapest ****tyest lathes you can imagine, certainly no Holbrook or monarch accuracy there.
from my own experience wonkey drunken ragged threads were usually caused by me, wrong die, wrong material, wrong speed, wrong lubrication ( wd40 whilst ok on Ali isn’t a high pressure grease, though to be fair it does work and whale oil is frowned on I’m told, I like whales they should be left alone imho)
id persevere myself, but with a better HSS die made in the US not the China version of HSS you can file!
mark

[Tundra Twin Track]

I made a sliding Die Head holder that fits in tailstock,it excepts Ridgid Heads,pic shows 3/4” NF in one pass in about 1 min.

[Tundra Twin Track]

For tapping this also fits in tail stock.

[Paul Alciatore]

I was going to mention those shutter (iris actually) style guides but as was already said, they weren't the best. They have been around for many decades and this demonstrates that drunk threads are a real problem. The first time I tried to thread a 1/4" rod with 20 TPI, the nut did the hula dance as it traveled down the thread I cut.

JoeLee's method looks nice, but if you don't have a lathe as the OP states, then where are you going to get them. And they won't work for everything, often other features will be different diameters so you will need a lot of different diameters, probably every two or three thousandths. And any slop between the die and that guide hole in the concentricity will show up in the thread.

If you want a good thread there is no substitute for starting it with a lathe. Pipe threading machines seem to work OK, but they can cost as much as a used lathe and are limited to pipe sizes. I am sure there are other expensive ways to use dies.

I think some of the responses are over complicating the posters question so let me rephrase it if I may.
What methods are available without a lathe to make die cut threads straighter ?

This is not a argument for what perfect threads are, or whatever, but a straight question
Joelee, Peter, and Fasturn mentioned a couple of techniques and the point about using a quality die is paramount to making acceptable threads

Personally , I use JoeLee' s method , but also have a very old style die holder that came with a cam operated shutter that closes around the stock before the die engages it whiuch controls the face of the die and the work piece

Rich

[reggie_obe]

. Pipe threading machines seem to work OK, but they can cost as much as a used lathe and are limited to pipe sizes. I am sure there are other expensive ways to use dies.

There are and have always been bolt dies available for pipe threading machines.

[J Tiers]

There are and have always been bolt dies available for pipe threading machines.

They do full profile, just like any die.

[Paul Alciatore]

Does that include 4-40, 6-32, 3mm, etc?

And is there a way to hold the stock when it is 1/4" diameter or less?

There are and have always been bolt dies available for pipe threading machines.

[reggie_obe]

Does that include 4-40, 6-32, 3mm, etc?

And is there a way to hold the stock when it is 1/4" diameter or less?

Smallest bolt die is 1/4"-20.

[Tundra Twin Track]

They do full profile, just like any die.

These are 3/4” NC dies that fit one of my Ridgid Die Heads.

[Bented]

Does that include 4-40, 6-32, 3mm, etc?

And is there a way to hold the stock when it is 1/4" diameter or less?

Common die heads are available to #0 diameter, you will not like the price however, and this is from the "Value Collection". A high end tool would cost far more.

https://www.mscdirect.com/product/details/82604075

As far as work holding is concerned, if you want to produce #4-40 sized components simply use appropriate sized equipment.

[Tundra Twin Track]

[QUOTE=Bented;n1978824]

Common die heads are available to #0 diameter, you will not like the price however, and this is from the "Value Collection". A high end tool would cost far more.

https://www.mscdirect.com/product/details/82604075

And I thought the Ridgid stuff was pricey!

[Bented]

And I thought the Ridgid stuff was pricey!

Automatic screw machine or turret lathe tooling used in production work. Never intended for maintenance shops or hobby shops.

A CNC lathe will produce small threads faster then single pointing a #4-40 feature on a part if the die head is held in the tool turret.

[Tundra Twin Track]

Automatic screw machine or turret lathe tooling used in production work. Never intended for maintenance shops or hobby shops.

A CNC lathe will produce small threads faster then single pointing a #4-40 feature on a part if the die head is held in the tool turret.

I was fortunate to find most of the Ridgid stuff at a very reasonable price,the Mount was built from Scrap Metal laying around the Shop including the Weed Eater Gas Tank🤓