Double or Single Flare Stainless

Hello - I am reading that stainless lines should never be double-flared. What is the consensus on this?

From what I understand double flare does work harden the material making it more prone to cracking at the flare - it's held together with the hardware here as well though.

It isn't easy to double flare stainless. But we've done it in our workshop for a few of the HPA project cars.

Assuming you're using it for brake lines if it's not going to be a double flare then consider a bubble flare?

Thanks, yes it's for brake lines. I'd prefer to go stainless, but I've read (and these courses note) that single flares are undesirable because of cracking. Speedway offers a nice stainless kit but it uses single flares with backup ferrules, which I don't think is street legal. I'd prefer to go stainless versus NiCop or steel, but I want to maintain street legality and safety in general.

Double flaring stainless should (from a metallurgical standpoint) work harden the material, promoting cracking. I assume this is why the single flare is prevalent. But I'm also not convinced compression fittings are the answer (that's what an AN single flare plus backup ferrule do...

All input is appreciated

In New Zealand AN compression fittings are illegal for brake lines for road use. I know things are different in the USA but I wouldn't recommend this.

You can buy annealed 304 stainless brake lines, or double annealed. This helps restore some of the material's ductility, making it easier to form and less prone to cracking.

As Connor said, you can buy different SS alloys, with different characteristics.

Use right material and double check for any flaws in the double flair, you may also find the cheaper tools are difficult to use nd get a good finished product.

Thank Gents, appreciate your insights.