2024-T3 tube cracking when flaring

[hurkME]

I've already asked this in the aerospace forum, thought I'd try over here. I'm trying to single flare 1/4 and 3/8 OD .035 thick 2024-T3 tubing and I'm getting cracking. I think the problem is in the tube prep. Does anyone has a working process; cutting, filing, deburring, sandpaper grit?

 

[makeup]

Try Swagelog they have a lot of info on pipe / tube preparation, or UKCOA they have a best practice guide book for small bore tubing

 

[iainuts]

I'm assuming you're refering to flaring 37 or 45 degree flared tube fittings.

The only times I've heard of cracking during flaring is when the tube end was cut using a tube cutting tool, the type of tool with a rolling cutter. That's because the tool work hardens the material at the end of the tube to some degree.

The way around this is to simply cut using a hack saw. There are special tools to clamp onto a tube which are used to guide a hack saw, I'd suggest using them. They clamp to the tube and have a slot for the hacksaw blade.

Deburr of course after using the saw. Hope that helps.

 

[Maui]

Have you tried using a double flare tool instead of the single flare?

 

[hurkME]

Thank you guys for your help! I was able to convince my technician that the problem was with deburring after cutting. After a little experimenting, he has been able to flare without cracking the tube.