Cutting Aluminum Sheet/Plate

This topic has 36 replies, 16 voices, and was last updated 23 July 2010 at 22:41 by Gorak.

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19 July 2010 at 01:36 #53566
Gone Away
Participant
@goneaway
I need to cut some pieces approx 16 x 11 from 1/8 thick aluminum (alloy) sheet. The sheet I’m starting with is a recycled large panel from a local surplus store. It has (non-useful) holes along each edge so I’m having to trim those too.

I’m doing this using a jigsaw (sabre saw) with a metal-cutting blade. It’s sort of OK …. not terribly quick and I’ll have to trim the edges on the mill even using an edge guide.

I wondered if there is a better way – in particular whether it’s possible to use a tablesaw in some fashion. For the job I’m doing, straight cut edges from a tablesaw wouldn’t need any further machining. I don’t know whether anyone ever does cut sheet metal this way and if so how it is done safely.
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19 July 2010 at 01:36 #15476
Gone Away
Participant
@goneaway
19 July 2010 at 03:29 #53567
russell
Participant
@russell
i’ve not done it myself, but i have seen a demo of cutting about 3″ x 12″ al bar (not sure what else to call it!) using a circular saw. The only concession i can recall to it not being wood was use of a spray lubricant, applied by hand.

I’ve also seen Al extrusions cut dry with an apparently normal mitre saw.

hope this helps….

russell
19 July 2010 at 05:24 #53570
Ian S C
Participant
@iansc
Hi Sid, I think for a staight cut, a carbide tipped circular saw would be OK. My saw is out of action at the moment, or I’d go and try it out.Ian S C
19 July 2010 at 07:24 #53573
JasonB
Moderator
@jasonb
If you do use any form of circular saw blade make sure it has negative rake teeth as the usual (for wood) teeth have positive rake and will tend to draw the metal into the blade.

A bandsaw would give a straighter and neater cut than doing it freehand with a jig saw but would still need a light skim with a mill.

Jason
19 July 2010 at 09:20 #53579
KWIL
Participant
@kwil
Depending upon the alloy it is possible to use an ordinary hand tenon saw for straight cuts. Do not use your cabinet makers best saw! Smooth gentle cuts with the minimum of pressure.
19 July 2010 at 09:26 #53581
Niloch
Participant
@niloch
I’m not suggesting Mr Herbage that you go out and buy one of the following especially for the task you have in hand but, maybe for future reference, you might find these saws have amazing capabilities.

These are available in the UK from B&Q but I believe world wide availability also exists. I have one of their sliding mitre saws and never cease to be surprised at its capabilities, e.g. sawing through thin wall stainless steel curtain poles.

Edited By Niloch on 19/07/2010 09:35:13
19 July 2010 at 10:39 #53584
Martin W
Participant
@martinw
Niloch

I have seen these blades advertised and wondered just how effective they were. It appears from your post that they really can be used on the harder metals with little problem. I have used my chop saw with an as supplied TCT wood blade to cut aluminium round stock up to about 2ins dia with no problem, the blade is designed with anti kick features.

For those interested in using one of the blades described by Niloch a supplier of these blades in various sizes can be found here Blades. Usual exceptions etc.

Niloch what does the swarf look like? When I cut the Ali bar using a wood/GP blade it produced blade width chippings about 0.25ins in length that were like confetti.

Cheers

Martin

Edited By Martin W on 19/07/2010 11:00:53
19 July 2010 at 10:57 #53585
Niloch
Participant
@niloch
Martin – I’ve never cut aluminium on my Evolution but I have cut acrylic (perspex/plexiglass) on my DeWalt chop/circular flip saw and the ‘swarf’ in that instance certainly looked like confetti. I did lower the angle of attack though and had a 300mm dia. blade with about 80 TC teeth.

I happened to be in B&Q during one of the Evolution demonstrations and even the demonstrator was a little surprised that it had gone through the stainless steel curtain pole! I wouldn’t have wanted to get in the way of the very hot ‘swarf’.

I bought the Evolution saw as a ‘family’ saw. It resides permanently at one of my sons-in-law’s houses. So far it has helped build three garden decks, laid three oak floors etc. Bought on a Wednesday morning at B&Q when those of us who are old enough benefit from 10% discount on top of an existing special offer it was, as they say, cheaper than chips.

Usual disclaimer by the way.
19 July 2010 at 11:05 #53586
Billy Mills
Participant
@billymills
Hi Sid, I would own up to having used a TCT circular saw to cut Ali but the regular blades designed for wood are far too fierce- so even a very slow feed rate can be very hairy. Would not recomend at all unless you are very careful, expect large chips flying, full eye protection vital.

As Jason has said, a negative rake blade is what is needed, some triple chip blades are rated for Ali ( they are very good on Perspex and some other ‘difficult’ plastics too) but there are also some abrasive blades that are said to be useable on Ali. The Evolution blade IS fantastic as a cut almost anything blade and is great on a chop saw however Evolution say that the blade should only be used on their saws- I wonder why?

There is always the sheet metal saw- a nice new blade will finish the job quicker than you will get a new blade and you get a bit off the waistline too.

Regards,

Alan.
19 July 2010 at 11:27 #53588
Niloch
Participant
@niloch
Posted by Alan Gray 1 on 19/07/2010 11:05:30:

Evolution say that the blade should only be used on their saws- I wonder why?

Alan – am I not correct in suggesting that the r.p.m. of the Evolution machines is slower than the regular?

Our ‘family’ saw is not here for me to check.
19 July 2010 at 12:28 #53589
Martin W
Participant
@martinw
Hi

I should say that when I used my chop saw for Ali things were firmly fixed, clamped and that I was wearing all the necessary protection, high impact eye protectors, ear defenders, boiler suit with no dangly bits, etc and took it very gently. The cut was clean with a nice surface finish with no sign of dragging or snagging and blade tips showed no sign of pick up often encountered when machining Ali without cutting fluid.

I DO NOT recommend that others follow my example as if things had gone wrong the results could have been disastrous but in mitigation I needed what was effectively large washers/spacers with reasonable accuracy in a hurry and I’m afraid that ‘When the devil drives needs must’ was my excuse and the blade I chose did have anti kick back features. Secondly at the time the Evolution product was not on the market at the time otherwise I would have tried their blade. Again usual disclaimers etc.

Best regards

Martin

Edited By Martin W on 19/07/2010 12:32:28
19 July 2010 at 14:15 #53592
Jeff Dayman
Participant
@jeffdayman43397
Hi Sid,

The jigsaw, while slow, is a pretty safe and reliable way to cut heavy aluminum sheet.

An arborite-cutting or carbide plywood blade will likely work OK on the table saw for aluminum, but great care must be used to avoid jamming the blade. If it jams, serious injury can result. I have a friend who was badly cut and bruised when this happened and it also wrecked his saw.

A far safer way to cut the sheets would be to take them to your local Metal Supermarket and ask them to shear them for you, or to a machine shop where they can bandsaw them.

If you were closer to me here in Waterloo Ont. you could drop by here and I’d bandsaw them for you.

JD
19 July 2010 at 23:08 #53622
Gone Away
Participant
@goneaway
I confess that I seem to recall a similar discussion on another forum some years ago although iirc that involved sawing bar stock. The impression I came away with then was that it might be possible with a lot of if-and-buts but was at least potentially dangerous and probably best left to the more adventurous souls.

I thought I’d ask here to see whether anyone had blazed a trail in the meantime but I’m getting the same impression as before (and I’m not that adventurous). I’m also more than half way done with the jigsaw. The main thing the tablesaw method would have given me is straight, finished edges (as finished as I need them). As it is I’ll have to finish them on the mill …. and some edges are longer than the table travel so I’ll have to do it in stages .

Anyway, thanks to all for the inputs.
19 July 2010 at 23:47 #53624
Billy Mills
Participant
@billymills
Hi All,

Well as Sid has admitted to having a metal bandsaw in another post, it could be that the limited throat ( his sheets need to be 11″x16″) have stopped that.

Would agree that a nice metal cutting bandsaw is a very good and safe way of hacking sheet as the saw holds the work down on the table and you will have the top guide just above the sheet so no exposed blade. But you do need a real Industrial saw to do Sid’s job.

The jigsaw might struggle a bit with 1/8″ Ali- but worth a try.

Like Niloch, don’t have an Evolution to hand as I am at home, but I think the rpm is around 2500.The interesting bit is the tooth config, it appears that the Evolution blade is about clearance of the cut material and limiting the effective tooth feed. The finish is very good for the small number of cutting tips.

If I was Evolution I would want to sell motors with blades. But it would be good to know more.

Interesting that we all focus on “what power tool”, the sheet metal saw is still a good tool and handy for keeping fit, the wife is now quite good at keeping to the line. But you can run out of metal to cut.

Regards,

Alan.
20 July 2010 at 00:51 #53626
Gone Away
Participant
@goneaway
Posted by Alan Gray 1 on 19/07/2010 23:47:38:

Hi All,

Well as Sid has admitted to having a metal bandsaw in another post, it could be that the limited throat ( his sheets need to be 11″x16″) have stopped that.

Yes, absolutely. My 4×6 horizontal bandsaw can turned vertically but has quite a small throat – no more than 4″ parallel to the blade. It also has a very small table although that could be replaced with something bigger. In fact I could use a piece of this 1/8 sheet to make a larger table. Of course I’d need to find a way of cutting it out …. maybe use a jigsaw … hmm, wonder if I could use a tablesaw for that ….

BTW, the jigsaw is struggling a little but it’s funny. It will struggle a bit then free up and race along. I thought initially the blade was clogging but it didn’t seem to be (it’s a relatively coarse metal cutting blade recommended for “thick sheet”). This sheet was covered with a protective plastic film which I left on to … well …. protect it. I think that might be the problem – the plastic sheet softening and clogging the cut. Tomorrow I’ll try removing a narrow strip along the line of the cut so that I’ll still protect the metal from the sole of the saw but the plastic can’t interfere with the blade.

Edited By Sid Herbage on 20/07/2010 01:01:14
20 July 2010 at 04:30 #53628
Jim Greethead
Participant
@jimgreethead
Yes Sid, you can cut aluminium using a carbide tipped saw used for wood. I have cut 12 mm aluminium on my saw bench using a 216mm 60T blade with 10 degree positive rake with no troubles. And I did it before I read (somewhere) that you need to use a lubricant so it was all done dry.

I also found a blade called a Diamond (brand name) Multicutter. This is a 100mm diameter carbide tipped blade for cutting aluminium, PVC and Fibreglass at up to 7000RPM. I have fitted it to the slitting saw arbor in my milling machine and used it to cut 12mm aluminium. It gives a great surface finish. And it is fast – just slow enough to let the chips clear the teeth. And it cost $15.

On saw bench, I now have another blade. It is a MetalSonic Part No MSB1602040 160mm 40T blade that will cut steel, aluminium, plastics, wood (solid, ply and MDF) even with nails in it much faster than anything else I have seen. I have used it to cut 6mm mild steel both cross cut and ripping. I have not be brave enough to fit this monster to the slitting saw arbor but would like to hear from anyone who tries it – it should work.
20 July 2010 at 07:30 #53630
david kitchen 1
Participant
@davidkitchen1
Hello Sid

If you are to machine the edges after, try a local sheet metal worker and ask if they can cut it on their guillotine. No stress, no danger, cheaper than a multi-tooth blade, and straight.

David
20 July 2010 at 08:56 #53633
peter walton 1
Participant
@peterwalton1
The evolution saws can cut metal but it appears that this is limited to thin material.

See ebay listing 370400075055 this shows a large 355 mm cut off saw speed if blade is 1450 rpm.

Another way to cut ally sheet is with a nibler, you can get attachments for drills. These can cut with little distortion of the sheet but get some ear defenders as the noise is FAIRLY loud!

Peter
20 July 2010 at 10:19 #53638
Gordon W
Participant
@gordonw
Interesting thread this, I’m using a cheap little jig-saw, with a fairly coarse “aluminium cutting” blade(makers description) this works fine on 1/2″ aly with parafin lube, use a fence for straight lines. Some time ago I cut some plate, 1/4″ I think, on a small table saw with a tipped gen. purpose wood blade, this worked well, but only with the blade hight set just over the matl. thickness, maybe the extra width of cut helped?
20 July 2010 at 11:26 #53644
Ian S C
Participant
@iansc
Peter, I think you would have a problem cutting 1/8″ aluminium with a drill attachment type nibbler, a heavier industrial one OK. Yes they are great, used to use an air powered on for cutting Alclad for aircraft skins, only problem is the cresent shaped chips that fly all over the place and get stuck in the soles of your shoes. A friend modified a fishing boat to a live on launch, and opened a doorway in a bulkhead(5/16″ steel plate), using a nibbler, I suppose most people would use gas.Ian S C
21 July 2010 at 00:53 #53666
Gone Away
Participant
@goneaway
Well …. I finished cutting out the plates with the jigsaw. I left them a fair amount oversize since the finish is a bit rough and not very straight even with a guide fence. I then considered how I’d mill the edges to finish them. The table travel is only 10″ so it would need two setups for each edge. Plus I could foresee difficulty clamping as the plate would have to hang over both the front table edge and one end.

After briefly considering using a router table with a milling cutter in the router and a speed control (I’ve seen it done), I thought “what the heck” and decided to try trimming the sides on the tablesaw after all. And it was fine – no grabbing or kickback. On some sides I took a minimal just to straighten them using one edge only of the saw blade. On other sides I needed a full cut using both blade edges. In either case, I experienced no problem and now wish I had done everything on the tablesaw from scratch. It might have been a little more difficult working with the full size sheet but I think it would have been OK.

I used the blade that was already on the saw (10″ 60T 1/8″ kerf – nothing special) with minimal tooth penetration through the material. I cut through the plastic protective film on the sheet and used no lubricant. I “cringed” rather less than I would cutting particle board. I wore a full face shield (and sheet metal gauntlets) but there were no flying chips anyway.

So, yes, it can be done and thanks again to all.

Edited By Sid Herbage on 21/07/2010 00:55:58
21 July 2010 at 01:16 #53668
Billy Mills
Participant
@billymills
Sid, do your metal cutting jigsaw blades have a wavey form? there are plain sided blades and wavey ones which cut a wider kerf for clearance. The wavey ones do not jam as easily and will produce curves easily. ( same as hacksaw blades) Never had a problem with the protective plastic film. Some people have used candle wax as a blade lube for soft Ali which does tend to bind up more than other metals.

Have used a Makita electric nibbler quite a bit to open up complicated holes in PC cases. Very handy tool that saves hours but the crescent shaped swarf is an absolute B****D as it is very sharp, but the swarf is large and better than steel dust in this application. The JN1601 nibbler is the stepped oscillating shaft in slotted cylinder type which limits the thickness to a safe value for the tool to be 1.6mm so too small for Sid’s job. There is another type with a tooth and two fixed faces which will accept thicker work and is often air powered, again very useful.

If you clamp a bit of angle against the job and guide the nibbler against the angle you can produce a fair straight cut instead of the drunken walk job. Nibblers can mark the surface as -especially the single tooth type- put the shearing load onto the Operator side of the sheet. Same as a jigsaw but the shear is much greater.

Regards,

Alan
21 July 2010 at 01:52 #53671
Gone Away
Participant
@goneaway
Hi Alan,

They are wavy but not a lot – more due to tooth set really. They are Bosch T118B see:

http://www.boschtools.com/Products/Accessories/Pages/BoschAccessoryDetail.aspx?pid=326

One of the problems with using a jigsaw is that the blade itself is so flexible and not particularly well guided (at least on this jigsaw). Once it starts curving off, it’s hard to control. The sheet is also somewhat difficult to clamp. Cantilevering over the edge of a bench gave me a lot of vibration of the sheet. I ended up clamping it to both jaws of a B&D Workmate (one of the original British cast aluminum (or aluminium I guess) jobs. I had to clamp the jaws first onto a piece of 1″ bar at each end to take the play out of them and at that they weren’t precisely level. Partly because of that, I also had some difficulty clamping a fence tightly enough to resist the side force of the jigsaw when it started to wander to one side.

All in all, as I said in my previous message, I’d have been better going with the tablesaw from the start for large pieces like these.
21 July 2010 at 12:51 #53681
Lawrie Alush-Jaggs
Participant
@lawriealush-jaggs50843
Hi Sid

I wrote an article about this topic last year and submitted it to the Editor of MEW for publication. As it hasn’t appeared, here it is without the pictures.

In summary, go and buy yourself a cheap electric saw and put an either put an aluminium cutting blade in it if you are going to do this on a reqular basis or if it is an occasional thing, just use the TC blade that comes with the saw.

Cutting large pieces of aluminium

In issue 151 of MEW Dave Fenner talks about the difficulty he had cutting large pieces of aluminium for his metal mangle and suggested that someone might like to address the problem with an article.

I am not sure that it will stretch to a full article but here is some of my experience.

Some years ago a mate of mine bought a bank building when the Australian Banks were going through one of their “To serve you better” phases and shutting down loads of branches. The bank took out everything that wasn’t bolted down and left everything that was. Everything that was included all of the bits protective stuff that they put in, the shutters, heavy office panelling and the like. The idea according to one of the designers I spoke to later was that the staff should be in an area that was mortar proof. To that end the shutters are 10mm armour plate. The panels for the Manager’s office are 16 mm bullet resistant aluminium plate with a 6mm air gap and then another sheet of 6 mm bullet resistant aluminium.

Needles to say I am quite well endowed with 16mm and 6 mm aluminium plate as well as huge barbecues of 10mm armour plate.

I wanted to build a multi-purpose saw/router/planer bench. I had had a Triton for over twenty years and never been entirely satisfied with it. I decided on a single plate 900mm square x 16mm thick. I needed to cut it to size, square it all up and then cut a hole with a rebate in it to take a piece of 6 mm plate. This was before I had a milling machine or a lathe bigger than a Unimat SL.

I made the beast and it works like a charm. The router bolts onto a plate and drops into the hole. Similarly the 9 1/4” circular saw and the 75mm Makita planer.

This is what I found out about cutting large pieces of aluminium and the tools I tried.

1                     Hacksaw

2                     Jigsaw

3                     Reciprocating saw

4                     Circular saw

5                     Band saw

6                     Abrasive disk

7                     Water saw

8                     Router

Test method

I tried cuttibng with each tool except the router and water saw. I don’t have any aluminium router bits at present and I also do not have a water saw.

I laid a piece of 900 mm wide 16mm bullet resistant aluminium plate on a pair of saw horses and with my daughter manning the timer cut with each tool for a period of one minute. You can see the results in photo AC1 and AC2. The cuts from bottom to top are as per the list in table 2

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