Thru axle material, do soft alloys (6061) threads last long time?

[musiclover]

Hi,

Just found out that thru axles that I bought were 6061 T6 which is a softer type of alloy.

Did you have thru axles made out of it? Do threads hold fine? I suppose this is the only potential issue as I doubt this will affect the "stifness"...

In hindsight, I probably should have got 7076 or at least 7005.

[youngs_modulus]

6061 is a fine material for a thru axle—the threads will last just fine. Plus, 6061 is much more resistant to corrosion (and stress corrosion cracking) than 7075. That's why many hub manufacturers use 7075 for the axles but 6061 for the shells.

As far as I know, no one makes axles out of 7005. In fact, I'm not sure I've seen 7005 used anywhere but bicycle frames. Its main advantage there is that it doesn't have to be heat-treated after welding.

You're right that 7075 and 6061 have nearly indistinguishable stiffness. Your 6061 axle is just fine.

[musiclover]

Thank you. Interesting. I thought the benefit of a softer alloy could be that it will be gentler on dropout threads...