Hobbyist Guides – Page 3 – Make It From Metal

I felt compelled to write this article because I've seen so many people struggle with cutting aluminum plate. I may or may not have been among these people. As a general rule of thumb, anything that would be considered a high performance tool for wood will also cut aluminum plate. Even there, though, there are exceptions. Let's start off with some of the ideal tools that will work for most applications, a few more that work well for specific applications, and then some tips and tricks. Heads up: I added some links to Amazon so that you can see exactly what I'm talking about for tools and blades. It's easier to just post a link to what works than spend a few paragraphs describing them. Band Saw Of course this makes the list, but it's actually not always the ideal tool. This is best for thick plates, about half an inch or thicker. The nice thing about band saws is that they can work well for really thick plates - I've cut plates 8" thick without issue. When you're cutting aluminum on a band saw, you'll want to crank the blade speed up to 250 feet per minute. If your saw has variable speeds, just consult the chart. Usually it's a matter of moving a belt to a different sized pulley. In terms of blades, you'll want to make sure that you have something with a lot of space between the teeth. The designation for teeth spacing is TPI - Teeth Per Inch. The ideal TPI for cutting thick aluminum plate is 10-14. Technically anything will eventually get through the plate, but this is where you'll see the best performance. If the tooth pitch is too fine, there's a high risk that the aluminum chips with clog the blade. If the pitch is too coarse, cutting will be slower since there are less teeth engaged and working to remove material. Better to err on the side of too coarse. Either way, the main problem you want to avoid is clogging the blade. Make sure that you use coolant or a light oil like WD-40 to lubricate the cutting and prevent the chips from gumming up your blade. Circular Saw This is actually one of my preferred ways to cut aluminum. It is stupidly fast and it leaves a nice, clean cut if you can hold it steady. There are more safety concerns with this one, though, so let's address these first. It's always good to keep your fingers and face more or less how they're supposed to look. For starters, clamp the plate down if you can. C-clamps that hold the aluminum on a table is a great way to keep things steady. You might want to put a couple of wood blocks sandwiched between the table and the plate so you don't slice up your table. This is especially important if your table is steel. These chips really come out fast and hard, too, so safety glasses won't give you enough protection. Use a full-face mask instead (ideally something that is anti-fog and will keep chips from coming in the sides and top). Gloves can be a good idea too. I usually just slap on a pair of welding gloves. Aluminum can be pretty sharp stuff. Ok, that should cover you for safety. Now for blades, definitely use something with carbide teeth. Usually circular saw blades that are intended for non-ferrous metals like aluminum are packed with a ton of teeth. This will actually help you to keep the saw steady. Having a low tooth count on a circular saw blade can be... intense. It's really worthwhile to spend a couple bucks on a proper blade. For around $20 to have the right tool, it just kinda makes sense. The cut will be cleaner and it's much safer to operate. This saw blade works great. There's a good grade of carbide tipping the teeth so they're not too likely to chip out. It's got a few other details like the proper tooth angle and blade thickness that just make the cutting go better. You'll definitely want to pick up some lubricant, too. WD-40 works good. You can also get the wax sticks, they last a little longer. If you don't use lubricant, it's pretty likely that the saw will plug up and wreck the blade. This works amazing for things like diamond plate, but I've cut as thick as 4" aluminum (had to cut it from both sides to get the blade deep enough) and it worked just fine. This is a handy trick for things that are too big for the band saw. Jig Saw or Reciprocating Saw Obviously the circular saw is great for straight cuts. Not so much for curves. Depending on how tight the curves are, either a recip saw or a jig saw will be the tool for the job. Both have pros and cons. The recip saw has a longer stroke and more power so it will cut faster. The jig saw can make tighter turns. I actually find that I can usually get a straighter cut on thin plate with a jig saw. It's a little more ergonomic and less aggressive so it's less likely to wander. These don't really work so great for thick plates. Doing anything over 3/16" or 1/4" will start to get pretty brutal. Obviously, make sure you're using a blade for metal, not wood. I find that wax works a little better than light oil for these tools, since it stays on the blade for longer. Tips and Tricks Use a guide if you want a really straight cut. I like to clamp some flat bar to the plate so I can push the circular saw against the straight edge. A 2x4 or straight piece of wood can work too. It keeps the blade dead straight so that the cut comes out really clean. It's also less likely that the blade will bind or buck. Wax lubricates the blade for longer, oil spraying is more convenient. I'm not talking about candle wax. Get a proper metal cutting wax and keep it on your shelf. The nice thing about WD-40 is that you can use it for literally everything, so you should already have a stash. Use a good quality circular saw. Unless you're looking for a reason to upgrade what you have. If that's the case, I understand. The reason for this is that there will be a lot more vibration when you're cutting aluminum compared to wood. It puts more wear and tear on your saw. If it's not tight and strong, your saw might not hold up too long. Basically, don't expect to get long-term use out of a $20 skill saw when you're cutting aluminum. Mind you, if you're only doing a couple of quick cuts then you should be hunky dory. Tape anything that you don't want to scratch. The chips are going to get everywhere, and sliding them along a nice brushed aluminum surface is going to make it look very ugly. If you want to keep the surface nice, pretty and scratch-free, use masking tape to keep the surface protected. If you're cutting diamond plate, do it pattern side down. Keep your saw shoe on the flat surface, not the bumpy diamond pattern. It'll just be easier. Clamp it! I know I said this before, but it's worth mentioning twice. Clamp the aluminum to a work bench so it doesn't bounce around. There will be a lot of vibration compared to wood so it's worth taking a few extra minutes to set up for a good cut. All right, there you have it. These are my go-to ways of cutting aluminum plates. I've used all of these methods dozens if not thousands of times, so they really do work. Do you have a question? Or another way of doing it? Post it in the comments below and get the conversation going!