Bushwalk Australia

Found a metal bent tent peg of short length while bushwalking. It would not bend straight by hand as aluminium pegs do.
After sitting on a shelf for a few years - just now, I tried hammering it straight.
It snapped cleanly after 4 or so hammer blows.
Gold coloured outside, square profile. Snapped ends are a dull silver, and are granular in appearance.

The now-broken peg is heavier than an any aluminium peg I have, yet lighter than any steel peg
- so I assumed on finding it that it was titanium; but if titanium (or otherwise); why did it snap?

Stressed beyond its limits.
Look up metal fatigue, Young's modulus...

If I bend the small light weight pegs for my Hubba Hubba, I cannot bend them back without breaking them.
This seems to be a property of some light weight hardened materials.

There are numerous grades of aluminium alloy - and titanium alloy, for that matter. Some err toward softness and ductility, others towards hardness and thus more brittle. Lots of alloys get heat treated too, which further hardens them. Hardening means if bent they'll shear and/or snap, rather than stretch.

Most 'quality' aluminium alloy pegs (Eastons, GroundHogs) seem to be 7075 series, which is definitely on the 'harder' end of the spectrum. Makes sense for an application where bending is generally undesirable.

That said I still have the old alloy sheephooks from my long-disintegrated Snowgum tent and those things are soft-as... easy to bend, easy to hammer back into shape, like the cheapo steel pegs of yore. They feel like 6061 or some other 6000 series alloy (typical for general fabrication, more weldable and machinable).

"Snapped ends are a dull silver, and are granular in appearance."
That sounds like an aluminium peg , I have seen that with fake Grounhogs (like the one in the photo) and similar cheap pegs.

(that white inner part visible there is dull grey in reality).