Cutting Aluminum?

Saburou · Post by **Saburou** » Wed Sep 10, 2008 4:57 pm

I'm making some Japanese armour - lots of long (20"+) thin lames for the body. I'm cutting it with a power shear (like this one http://www.harborfreight.com/cpi/ctaf/D ... mber=99735 only corded).

The problem: the aluminum (.100 5052) twists as I cut it and it's a son of a gun to twist flat again.

What do y'all use to cut aluminum? How can I fix my problem here without it work hardening too much?

Justin Andrews · Post by **Justin Andrews** » Wed Sep 10, 2008 5:11 pm

Either my power nibblers or my B1 Beverly Shear depending on my mood.

The B! warps the metal a little, but its really nothing because by the time I've beaten the living heck out of it, the tiny amount of warping is insignificant...

AngusGordon · Post by **AngusGordon** » Wed Sep 10, 2008 6:22 pm

When I made my lamellar, I bought a non-ferrous metal blade for my table saw, then WITH PROPER SAFETY EQUIPMENT IN PLACE (leather apron, sturdy gloves, safety glasses w/side shields AND a grinding mask) I cut strips from the sheet with my rip fence set to the width I needed. Maybe not the most sound advice, but that's how I did it.

The blades cost 7.50 at HF.

Gryndar · Post by **Gryndar** » Wed Sep 10, 2008 8:39 pm

Angus is right, I build aluminum boats for a living, and a band saw with a fence set up to the right width is the fastest way to go, If you cant find a bi-metal blade a blade with 10 - 14 tpi for wood would do, but it wont last for more than an hour total cutting time.
Barry

marcus the pale · Post by **marcus the pale** » Wed Sep 10, 2008 9:10 pm

I used to use a band saw for cutting aluminum as a former machinist, for the thick stuff I've even used a skill saw. I imagine a table saw would work just as well, with the right blade and safety equipment. I was surprised how well it came out the first time I tried it.

Looking to drop the steel kit eh?

marcus

redrook · Post by **redrook** » Wed Sep 10, 2008 9:46 pm

Saburou,
When I cut long thin strips of metal, they nearly always twist. I have found that putting one end in a vice and grabbing the other either with my hands or pliers, that I can usually get the twist out all at once. Simply twist in the opposite direction. YMMV

Richard

sha-ul · Post by **sha-ul** » Wed Sep 10, 2008 9:59 pm

I would probably use my bands saw, but if you have a BUNCH to do. would it be worth say $15-$20 to have it all made into strips?
if you think that is a fair price, call around to your local fabrication shops,& metal suppliers. Aren't you a teacher? try the shop class& see if they have a stomp shear. if the aluminum isn't too thick you could get nice-long-straight-strips in a hurry.

bottom line, find a shear that can handle the width of the material you have. in 15-30 min you will have a pile of nice strips :wink:

Halberds · Post by **Halberds** » Thu Sep 11, 2008 1:28 am

I agree with sha-ul, find a place with a shear that will cut your thickness.

You will get nice clean cuts with minimal deburring required.
While you are at it get wider strips cut for your COP.

Which reminds me to use the shear at work to cut up some 14 ga. spangen bands and splints before they ship it off to Florida.

Man talk about a nice shear it is electric/hydraulic with a digital read out on the back stop. You just push a button and it sets the depth of cut to .005 accuracy.

Hal

AaronCarter · Post by **AaronCarter** » Thu Sep 11, 2008 3:16 am

Halberds wrote:Man talk about a nice shear it is electric/hydraulic with a digital read out on the back stop. You just push a button and it sets the depth of cut to .005 accuracy.

Hal

When I was doing steel work we had one, but ours was acurate to within about 3" and square within a foot and a half depending on who had used it since I calibrated it last

Saburou · Post by **Saburou** » Thu Sep 11, 2008 4:58 am

Thanks gents!

mattmaus · Post by **mattmaus** » Thu Sep 11, 2008 7:49 am

Depending on what I'm doing the bench shear or the jigsaw.

Jigsaw shouldn't warp it like you're describing.

Thing is, the AL gets a lot hotter than steel, a lot faster. When you're sawing it, that means it gums up between the teeth and fuses itself to the blade. You end up with this blade that has a crusty hard aluminum edge that won't cut anything. Fewer TPI seems to alleviate this a lot. My guess is that the bigger space between teeth can clean itself out easier.

But a big stomp shear with a backstop is the way to go for lots of strips.

Scott · Post by **Scott** » Thu Sep 11, 2008 10:25 am

A few months ago, I had to cut the centergrip hole out of an aluminum blank. I used a handheld jigsaw. I, too, noticed that the aluminum clogged up the blade. I kept having to use a wire brush to clean it out. After a bit of this, I tried spraying WD40 on the blade & cut line. This kept it from gumming up the blade. Either it kept it cooler or kept the chips from sticking. Either way, it made the cutting much quicker.

- Scott