bending brass

[Rob DiStefano]

i've got a pedersoli pistol kit where the brass trigger guard is way out of shape and needs to be bent to fit the stock inlet.  i think that attempting to bend it without heat will work harden it, make it brittle and prone to snapping.  in terms of heating it, i'm thinking of putting it in a vise, heating with a propane torch and slowly bending, then water quenching to cool it down, check the fit, keep heating/bending/coolig 'til it both fits the inlet and clears the trigger.  n'est pas?

[Keb]

I wouldn't quench it in water. Holding it in a vise will act as a heat sink also. I'd just hold it with pliers or vise grips away from the rear of the guard and heat. Just let it air cool. Lay it on an anvil if you have one. This will pull the heat out of it. Don't lay it on the kitchen table if you are married. This should anneal it so you can bend it cold without breaking it.

[Rob DiStefano]

real good scoop, joe - thanx.  how much heat - not cherry red?

[rollingb]

real good scoop, joe - thanx.  how much heat - not cherry red?

Heat your brass until it just begins to "glow", then let it cool.  

[Rob DiStefano]

gotcha!    thanx rondo!

[James Kelly]

Whatever you do, do all your bending while the brass is at room temperature.

When brass is bent hot, most of it tends to break or crumble.

This is because most brass has a little bit of lead in it. When you heat the brass, the lead melts, or at least softens, and goes to the crystal (grain) boundaries. Either it embrittles the brass or you are bending a bunch of crystals with liquid lead sort of sticking them together.

Why lead? Brass castings have lead added to improve castability. It reduces leaks in plumbing fixtures, except in California where they don't like to drink that lead. Most brass in bar form is going to be machined, a little bit of lead is added for machinability. Likewise plate or heavy sheet tends to be engraved, or have keys machined out of it. So a bit of lead is added.

[Hank in WV]

I know this is an old post, but, be very careful bending near that screw hole. It will want to fold there as it is the weakest point.