Re-hardening brass?

[Ray Dunakin]

Can someone tell me how to re-harden brass? I have to heat it red-hot with a blow torch to get it soft enough to drill with a pin vise, and need to harden it up again so it won't bend too easily. I thought reheating it and quenching it in cold water was supposed to work, but doesn't.

[Design-HSB]

Hi Ray,

Brass can be cured only by machining. So by rolling, drawing, hammering and pressing it is cured. Each glow or greater heat also makes it soft again, quenching does not help there.

[greenie]

Hi Ray, why do you have to heat it up just to drill a hole, brass is very easily drilled with a new sharp twist drill.
You can even make your own old type of jewellers spade drill, that will eat the hard brass.

Have a look at this lot for inspiration on making your own spade bits.

http://en.wikipedia.org/wiki/File:Drill_spade_tiny.jpg

regards  greenie 

[billmart]

Ray -
The method used to harden brass is known as "work hardening."  Check out http://en.wikipedia.org/wiki/Work_hardening

I've used a pin vise and small drill bits to drill lots of holes in hard brass sheets.  I suggest a nice sharp bit, with several replacement bits on hand!

Bill Martinsen

[lab-dad]

FWIW:
I use carbine bits (from drill bit city) they cut like butter!
I can do them by hand but break them sometimes.
In the mill they last forever, or until I hit the bit with my hand or a tool..........
-Mj

[5thwheel]

There is something wrong with your drill bits if they won't drill brass. If they come from China they usually are of no value for drilling any thing but wood. If the brass is quite thick then it will take forever with a pin vise but it will drill.  If you are drilling small, thin stock and have annealed it by heating it sometime you can clamp one end in a vise and pull the other end with vice grips to sort of stretch it.  I do this all the time with brass wire when making wire spokes.

Bill

[Ray Dunakin]

Thanks. I guess I need different bits, the bits I've been using (from various sources) take quite a while to go through soft brass, with a drop of machine oil, and barely put a dent in hard brass.

I just placed an order for a couple sets of drill bits from Drill Bit City. One problem though, they don't seem to sell individual bits. Same with some other suppliers I've looked at. I hate to pay for a set when I only need to replace one broken bit. Can someone suggest a source for good quality bits, available individually?

[SandiaPaul]

What the others said...its not really practical to re-harden brass.

For individual bits watch ebay, just search for the size you want.  The shipping kills those deals though usually.
Mcmaster-Carr, MSC, Travers, and Enco all them too, but again shipping is deal breaker.

The carbide one Marty mentions are great and like he says very brittle.  Run them in a drill press or just be sure you are keeping it perpendicular to the work.

For small holes I like to use what is called a "pivot drill", its a watchmakers type drill:

http://www.esslinger.com/0-004-inch-to-0-050-inch-mascot-flat-pivot-drills-sold-individually.aspx

They are a lot more durable and don't grab like a twist drill.

Paul

sorry I see greenie linked to a page on "spade" drill, same as a "pivot" drill

[lab-dad]

Call Paul (or email him) at drill bit city. 847-419-1267
He can make up a "set" of whatever you want.
He just did that for me.
I think you will end up wanting more anyway!
Just tell him I sent you.
-Marty

[Bexley]

Jobber Length Drill Bits

Not all of the brands they carry are sold individually, so be aware of that.

[mabloodhound]

JTS also sells individual number drills.
http://www.jtsmach.com/jtswebshop/Pr_CuttingTools/D002.asp

[james_coldicott]

Hi Guys,

just my 2 pennies worth... I do a lot of brass modelling and think one thing that should be stated is that there is brass and then there is brass! A machinable brass is essential for our work. I used to use any old scrap brass I could lay my hands on and it cost me a fortune in drill and mill bits etc.

I now only use European Standard CZ121 (I think the US equivalent is C37710- from google) which is a brass alloy with lead included. Here in the UK all the brass from somewhere like Eileen's Emporium is CZ121 machinable brass. Unfortunately K&S is not and you will find your costly drill bits biting, snapping and blunting very quickly.

I wonder if this is why many people find working with brass difficult?

Hope this helps.

James

[Lawton Maner]

Just a thought, but might you heat a small part of the wire with a Resistance Soldering Iron?  The instructions which came with mine says you can vaporize small brass parts if not careful.  By using the tweezers, you could heat a very tiny piece of the wire, just where you want to drill the holes.

[Design-HSB]

Hi Ray,

I think it's much easier to just take a good drill and the correct suitable brass.

To work optimally so that my drill saws, and brass polish is semi-hard, but this brass breaks when bent.

Then there are softer brass, which can be etched, for example, and then also bent sawn optimally not only good, and can be drilled befeilt because it lubricates it.

Real good tool for editing is of course also needed.

For drilling machine I use such special CNC drills and so that I can then even with a 0.5 mm drill bring hundreds of holes in thick brass.


Machine drills in case of 0.5 mm to 3 mm.