thread inside a hollow cylinder 3

[vscid]

Which is the best thread style and type I can cut on a 0.02 thick 347 stainless hollow cylinder on the inside?
I want an extremely tight joint.
Thanks!!

 

[MadMango]

Your wall thickness is .02? What units is this .02 that you want to thread? You may want to consider brazing, welding or epoxy.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[Heckler]

I want an extremely tight joint.

lick your finger before you start rolling

We need a little more information to give you any suggestions.

Heckler
Sr. Mechanical Engineer
SWx 2007 SP 4.0 & Pro/E 2001
o
_`\(,_
(_)/ (_)

This post contains no political overtones or undertones for that matter and in no way represents the poster's political agenda.

 

[vscid]

0.02 is in inches.

 

[rb1957]

clearly at 20 thou wall cannot support much of a thread, can you make it thicker locally ?

 

[CorBlimeyLimey]

.02" wall thickness????? The thread depth of a 1"-20 UNEF is .027".

What is the I/D of the tube?

What will this "thread" be mating to?

What forces will the connection be subjected to?

Can you quantify "extremely tight"?

Basically ... what are you trying to do?

 

[KENAT]

Agree with others more info required, especially diameter.

You'd theoretically be able to come up with a 'special' UNS that would do it for any given diameter but practically this may not be appropriate.

You can play games on this link for days but it may not be a practical solution.

http://www.boltplanet.com/Un/disclaim.asp?txtseries_page=UNS

You say cut, I assume rolling something like a bottle thread isn't an option then.

KENAT, probably the least qualified checker you'll ever meet...

 

[SteveWag]

Knowing very little about diameter/pressure/material, you could roll a grove and use a Victaulic clamp/cap. Vics are used for Sched. 5 S.S. but your wall is even thinner, it’s a risk. The advantage is no metal removal, so no reduction in wall thickness. Depending on diameter, failure will be burst of the cylinder or swaging of the pipe end.

Steve Wagner

 

[eromlignod]

There is a specific Unified series of threads specifically intended for thin-wall tubing. Diameters run from 1/4" to 1" and the pitch is 27 tpi. It is a UNS thread, but it is included as a "selected combination" in the standard. The sizes are in the Machinery's Handbook. However, I don't think even this thread will work in your application since the threads are deeper than your wall. It's also just a standard machine screw thread, not a sealing pipe thread.

You're going to be limited as to how tight you can make any joint with walls that thin, no matter what the thread. This sounds like an application for an o-ring gland or a brazed joint.

Don
Kansas City

 

[rb1957]

i wonder if he could form his tube onto a thread ?
don't know how tight that'd be, and if the app is "nuke", don't think i'd like to think about it ...

if this is a permanent joint, bonding is a good choice

 

[MadMango]

Forming threads would be better than cutting threads for sure. Without further details about the application we can only speculate.

Is this a one-off item, or production?
Does the joint have to disassembled at a later date?
How much pressure is involved?
A "tight joint" for liquid or gas?
Etcetera, etcetera, etcetera

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?