Very fine threads

[Prokop]

Hello everybody,

I need to cut an SAE equivalent of M32x1 - give and take few since I will be making both sides myself. Could anybody please point me to where to find specs of such SAE thread and where to get the tooling?
What is the biggest size for tap and die? I do not feel like learning lathe threading on something that small.

Thank you

[Carld]

If your going to use a tap and die you don't need to know the specs of the thread.

You can buy the tap and die from MSC, Enco or any supply house.

For the size of the shaft and the hole to tap and drill you will find them on a drill chart or in the Machinery Handbook.

If your going to do machine work you need a Machinery Handbook. It's not an option, you need the information there in.

[TGTool]

Hello everybody,

I need to cut an SAE equivalent of M32x1 - give and take few since I will be making both sides myself. Could anybody please point me to where to find specs of such SAE thread and where to get the tooling?
What is the biggest size for tap and die? I do not feel like learning lathe threading on something that small.

Thank you

You are honestly better off biting the bullet and learning to do single point threading. You'll need it. 32mm isn't that small so there's lots of room to work on the inside thread and the 1mm pitch isn't very deep.

OTOH, if you're set on buying the nearest equivalent tap and die you need to ask for a UNS 1-1/4 x 24. The tap manufacturers will make you one if you pay them, and you can call customer service for MSC or McMaster Carr to set it up. The next best choice might be UNEF 1-1/4 x 18 which is closer to a 1.4mm pitch FWIW.

Good luck.

[J Tiers]

I'd call that a LARGE thread.

Yes, 1.25 -24 is the closest "standard" sort of thread.

[BadDog]

If you've got the machine that will do the thread, just jump in. That should be a pretty easy threading job, and it's really no sweat at all to single point. I'm about as green/armature as it gets, and even I don't bat an eye and single point threads. It seems a lot more intimidating than it is.

As for the tooling, can't help you there...

[SGW]

IMO, it's easier to cut fine (within reason) threads than a very coarse thread, and 24tpi or 1mm pitch is pretty reasonable. Don't be afraid to try! It's the way to learn, and nobody needs to know how many "learning experiences" end up in the scrap bucket....

And yes, get yourself a copy of Machinery's Handbook. An older, used edition is fine, if you can find one. Maybe better than the latest, actually, since a home shop is typically somewhat behind the technology curve. Not that much of the information changes from edition to edition, anyway.

[Spin Doctor]

1-1/4-24 would be close. I think it is listed in the Machinery's Handbook. Here it is
External
Class 2A
Allowance .0013"
Major Diameter 1.2487 max, 1.2415 min
Pitch Diameter 1.2216 max, 1.2173 min
Minor Diameter 1.1976

Internal
Class 2B
Minor Diameter 1.205 min, 1.215 max
Pitch Diameter 1.229 min, 1.2285 max
Major Diameter 1.2500

Page 1286 of Volume XIX

[Paul Alciatore]

That would be about a 1.25-24

For 1.25-20

Enco: www.use-enco.com
Tap # 319-6437
Die # 319-6506

OR

KBC: www.kbctools.com

For 1.25-24
Tap: # 1-372-432

For 1.25-27
Tap: # 1-372-434

Sorry, I am out of time for now. Search KBC for a die. And remember you will need a tap drill.

[SGW]

...You'll also need a honkin' big tap wrench and diestock. And something substantital to hold the work while you attempt to wind in a tap or turn a die that big. Really, I think it would be easier to do it on a lathe....

[sconisbee]

I would just jump straight in and single point it, maybe make a few practise runs first, and make the external thread first so you can use it as a guage for the internel...

Just got done doing a similar thread in Stainless on this part

http://i59.photobucket.com/albums/g2...ckFitting1.jpg
http://i59.photobucket.com/albums/g2...ckfitting2.jpg
The large diameter is 4" and yea i know the thread pic sucks but its not bad for a camera phone.

A 1" BSP thread comes out at around 33mm major diameter, and it was single pointed (did external too but havnt got a pick of the piece of tube it was raining and didnt want to bring a 6 foot tube indoors tonight )

As everyone else has said a 1mm pitch thread isnt much in terms of depth so it should be easy enough to single point, and its diameter gives you alot of clearance for when you do the internal thread. Threadings not all that hard once you jump in and give it a go and with a pitch like that you could even get away with plunging the bit as opposed to feeding in with the compound.


Good luck!