cutting brass sheet

[nigel jones 5Participant @nigeljones5]

Made my last loco cab and tanks from laser cut steel. My 5" tank needs .9mm brass sheet. Whats the best way of cutting it to shape accurately using conventional tools?

[nigel jones 5Participant @nigeljones5]

[Sub MandrelParticipant @submandrel]

Aero snips are fine for 0.6mm sheet, they may handle 0.9mm (they distort 1.6mm/16G too much). Set of three from Machine Mart for under a tenner, but be aware that one jaw is serrated. This means one of the sides of one edge of the cut is serrated as well. So orient the cutters so the serrated surface will not be visible on assembly.

Neil

[Ian S CParticipant @iansc]

Aero/ or aviation snips; because of the serrated edge they are not permitted to be used on aircraft. During WW2, in the USA where they were made, aircraft started developing cracks in the skins, started by the serrated edge marking the skin of the AC, I think in those days both jaws were serrated. I'v got a pair of cheap ones, no serrations. Ian S C

[Phil AshmanParticipant @philashman88468]

I used a piercing saw to do mine. You can cut to within a few thou of a scribed line, zero distortion, and cutting out window apertures etc is a doddle.

Phil

[KWILParticipant @kwil]

You can get brass, laser and waterjet cut if you want to.

[Sub MandrelParticipant @submandrel]

So aviation snips are OK for all but aviation applications

It is a funny old world!

Neil

[Mark P.Participant @markp]

Hacksaw and file, works for me.

Regards Mark P

[magpieParticipant @magpie]

There is a hand tool that causes no distortion by cutting a strip about 2.5mm wide with a blade protruding from a slot. I have two of them and use them for most small sheet metal work. I think the original version was called a "monodex"cutter but the later versions are better because the monodex was open ended and the ends tended to spread out and cause distortion once this happend. Lousy description so i will take a pic and post in the morning.

Cheers Derek

[AndyfParticipant @andyf]

I'd be interested in details of those, Derek.

Like your Monodex, mine has splayed out at the front, and no longer responds to being squeezed together in the vice, because the edges have got pretty battered over the years and don't cut cleanly any more.

Andy

[Ian S CParticipant @iansc]

I'v got a cutter similar to yours Derek, at first glance the look similar to a pair of aviation snips. A nibbler is a good tool for cutting thin metal, without distortion, they can be had as attachments for electric hand drills. Ian S C

[TerrydParticipant @terryd72465]

Hi Fizzy,

How about a sabre saw (aka jigsaw) with a fine tooth metal cutting blade. Protect the surface of the brass with two lines of masking tape either side of the line. Leave a few thou to file to final shape. I have also used a piercing saw but it needsa a steady hand and patience as well as a jewellers easily made vee block clamped to the bench – see here

Regards

Terry

[magpieParticipant @magpie]

Here are the pics as promised. I bought these cutters about 20 years ago from RS Components who still sell them, allthough they are quite expensive, and i am sure they could be bought cheaper from somewhere else. The RS stock No. is 547-773 I use them frequently and have only broken one blade (replaceable) in all that time. The pics show them cutting 16g ally but i would not recomend cutting brass or steel that thick.

Cheers Derek.

[magpieParticipant @magpie]

I I put the same pic in twice in the above post and do'nt know how to remove it. This is the one i meant to include. They allways show the cutter being used in the manner shown in the first set of pics, however i prefer to use them as shown above, IE holding the cutter underneath the workpiece as it is easier to follow the marking out this way.

Cheers Derek.

[Sub MandrelParticipant @submandrel]

I have the Machine Mart equivalent of the monodex. It is hard work, but I cut the air ducts for my Suffolk out of old washing machine with it.

I also spent half an hour cutting six inches off the drainer of a stainless steel sink and cooker unit for a camper van. It was the hardest metal cutting job I've ever tackled, but it didn't seem to damage the tool.

It has the same serration issue as snips, but worse, and you cut such a delicate line.

Neil

[Clive HartlandParticipant @clivehartland94829]

Theres no two ways about it, you are going to do a lot of drilling, filing and cutting internal shapes. So you are going to sweat and swear !

Its just a case of applying yourself and using whats to hand and making sure you support the metal as you cut it, one of the best ways is with a coping saw with a fine blade. Even a Fret saw can be used carefully, and you can follow curves very close to the line. This leaving very little metal to file off.

The support can be a piece of wood with a 'V' cut in it facing you and clamped to a solid bench.

At 0.9mm thick it is not hard to file but take care you do not get too keen with the file and go over the lines.

Clive

[The Merry MillerParticipant @themerrymiller]

 

Have you all forgotten the dear old "Goscut"

Len. P.

 

Edited By The Merry Miller on 17/11/2012 20:16:52

[Ian PParticipant @ianp]

Posted by The Merry Miller on 17/11/2012 20:14:36:

Have you all forgotten the dear old "Goscut"

Len. P.

Edited By The Merry Miller on 17/11/2012 20:16:52

Or the Abrafile!

I used to cut steel and aluminium regularly, mostly 16SWG, with a jigsaw. Its noisy though.

I tried various lubricants and found the best of the lot is hardboard! When cutting metal normally with a jigsaw the fine swarf gets hammered into the material by the jigsaw soleplate, using oil it retains the swarf as it stops being blown away and it ends up damaging the finished (sometimes painted) surface of the job.

A sandwiched a piece of 3mm hardboard (or thin ply) between the say and the surface stops most of the marking, the best bit though is that the sawdust acts like a lubricant. It is especially good on aluminium, the blade teeth just do not clog.

Some jigsaws are designed to be cater for being clamped upside down in the bench vice which is better for cutting precisely to a line.

Ian

[Brian Baker 2Participant @brianbaker2]

Greetings, I have tried a scroll saw, and it does work, but for rough cutting I suggest a bandsaw.

This cuts quickly and accurately, and with a decent blade will make all sorts of shapes easy to cut.

Mine handles 6 mm steel, cutting slowly, so brass is no problem.

I use a Clark 14 in throat 3 speed machine obtained from Machine Mart over 15 years ago, but they are still available.

regards

Brian Baker

[nigel jones 5Participant @nigeljones5]

Ive opted for rough cut to within 2mm with plasma then bolted piece of flat steel to line and removed rest with abraisive pad on angle grinder – come out spot on and good finish. Thanks for all the advice.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

If you ever do any more just profile mill them . Screw one or two plain plates to a plank and away to go . Apart from a little hand work to blend cuts around some curves parts will be ready to use . Any edges too long for one cut slide plank along against fence .

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