Thread: How to flatten brass bar

Brass ( and bronze for that matter ) comes in a huge variety of alloys, some can workharden vey quickly and become brittle, and will crack when hammered.. some, like alloy 260 is softer and more malleable.

Start out by annealing it, heat it to red hot for a bit and just let it air cool naturally, if you are in a hurry you can water quench quite happily, it's not like steel which needs to be cooled slowly to anneal

If it's just a twist, then try and straighten by un-twisting it.. if it's more distorted than just a simple twist then you might be able to flatten it against an anvil.

Do you have a flat surface you can use as an anvil?

And a hammer with a clean face? if the face of the hammer is all dinged up then you will just transfer those marks to the brass.. if the hammer is all dinged up, then polish the hammer face with flap disk, and buffing wheel..

Hammer it flat against the anvil as best you can, turning it over as you go, you don't need to hit very hard, just tap tap tap is all you need... when you are happy it's flat enough for your purposes, then anneal it again to remove the stresses, if you want to harden it then work hardening is the best way, that might mean hammering all over with light taps and skip the final annealing step... sort of like planishing..

Sand or lap flat and polish..


Regards
Ray

Thanks Ray

I had no idea about the annealing. Had a quick little read up on it and it makes complete sense.

I'll see how I go with just the twisting, and I've got a big honking thick block of steel that should do as an anvil for this task (I'll clean up a face first, like with the hammer) if push comes to shove...or tap in this case

I'll give the workhardening a crack too. But will I (should I) be able to do it on the thin edges as well? It would be good if a marking knife couldn't easily take nicks out of it.

And just to double check...if workhardening, I should anneal only once...at the start, before removing the twist.

Should be a fun little job with a few new things to try and learn.

Just to add to what Ray has said, you can use a flat piece of steel laid on top of the brass and hit that with the hammer. The heavier the piece of steel the better. I have a piece 75mm wide x 35mm thick and about 350mm long. It works a treat.

Phil

Ooh...a local fella...thanks too Phil. I'll give that a go as well if I can rustle up something suitable.

If you can't find anything, you can borrow mine. If you have time you could bring the brass around and we can give it a shot. I should be in the shed all day...fingers crossed .
You'd have thought I would have realised you were local


Phil

Gah. I miss my oxy

I've been trying for the last hour or so and I can't get the brass hot enough or remotely evenly with my wee propane torch. Tried it in a fire with even less of a result.

Time to PM Phil with a bribe me thinks.

I just wanted to send out another huge thanks to Phil/Steamwhisperer for surrendering a couple of hours of his own play time to help me out with this this morning. He's done a great job of annealing and flattening out a couple of these crappy strips for me.

It's always nice to meet another forumites, especially locals, and I learned a thing or two while I was there (and not just about metal) and got to see some great stuff (his big Weir boiler pump project looks brilliant).

A big thumbs up for a top bloke