Is it possible and what’s the best way?
Squashing it in a vice?
Trying to bend it back with pliers?
Anything else?

Using a proper hanger alignment tool

Get a proper big adjustable spanner, and gently bend it straight.

Works for a few goes with steel, works once with aluminium.

Bike shops have a special tool to check alignment, but you might be lucky.

once i used a rock and another flatter rock, still working today – thank god it was not a carbon hanger 😉

+1 crikey

Big adjustable spanner and some patience.

Stone, or in this case hammer, wins. 😀

Cheers.

Got an old cup-and-cone wheel or axle you don’t want? The thread is (usually) the same as the mech thread, so you can screw it in. This gives you a perfect lever for straightening it, but it also gives you a lovely straight edge to judge straightness.

If you want to make it even easier you can get something suitably straight and stick it into the dropouts while you bend. I use a bit of 10mm threaded bar just because I have it lying around and I can spin a couple of nuts onto it and have it stay in place. Then, just bend it all til the 2 are parallel.

Wot Northwind says. It’s as accurate as a hanger alignment tool IME. I’ve used both methods, an I discovered the old axle method independently. Bracing the dropouts with another axle not only keeps it all rigid, but it stops you closing the dropout up by accident too. 🙂