Even the cheapo epoxies are immensely strong and will do what you want. West epoxy is amazing stuff but comes in relatively large amounts.
The critical thing is mixing - you are trying to get two viscous fluids to mix intimately and that is difficult. Stir as much as you can - if it's a slow cure resin, warming it a bit will help. You need clean surfaces, so give the metal a wipe over with meths or (better) cellulose thinner, then don't touch it before glueing.
You can get even stronger bonding by heating the job once the epoxy has hardened. 70C for a few hours will usually about double the strength, but I wouldn't do that with wood.
But for a tool handle, anything you can find will be fine.