sheet of aluminum being cut

How To Properly Cut Aluminum Sheets and Plates

Aluminum is one of the more versatile metals and one that is widely used in DIY workshops and metal shops around the world. Despite being easily workable, aluminum does pose some challenges. In fact, it’s usually because aluminum is easy to work with that some beginning machinists can mess up their cuts. Aluminum is quite soft, heats quickly, and can warp or bend if not cut properly. At best, that leaves the machinist with more work. In the worst case, it can ruin an otherwise good project. That’s why it’s important to have the right tools, the right blade, and the right procedures to make the perfect cut every time.

The best tools to cut aluminum sheets and pieces

Metal Shears

Metal shears (or tin snips, as some of us called them growing up) are probably the most common tool for cutting aluminum. Many aluminum projects are small, quick jobs that just need some fast trimming. Shears are perfect in that situation. They don’t heat the metal, they can be maneuvered into tight spots for hard-to-reach cuts, and there’s no power requirement – take them anywhere to cut anything.

Circular Saw

Circular saws are easy to use and widely available. They work well for straight cuts on sheet metal, but they work best with specializedcircular saw aluminum sheet metal cutting blades. Circular saws aren’t the best choice for thicker sections, either. But for quick cuts and smaller sections, circular saws and miter saws are an easy and quick choice for sectioning aluminum, especially in preparation for more detailed work.

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Table Saw

With a built-in edge guide, table saws provide a way to cut a straight edge on sheet metal, including aluminum. Follow the same advice that you would for a circular saw – it’s best to use a dedicated non-ferrous metal cutting blade.

Jigsaw

Table and circular saws are best for straight, smooth cuts. Jigsaws, reciprocal saws and handheld circular saws are capable of cutting curves and shapes that table saws aren’t. Bandsaws also could go here as an even better alternative. However, they don’t offer the same security and power as some of the other options and rely more on the operator’s skill to keep the saw steady and produce a clean cut. The aluminum

Metal Brake

Metal brakes are specialist metal-cutting machines, but they use a slightly different approach. Unlike power tools, metal brakes use a bending action to flex and score the metal, causing it to break cleanly along a straight line. Metal brakes are large and can be cumbersome, but for sectioning long, straight sections of aluminum sheet metal, they’re one of the best options.

Hacksaw

A hacksaw is a handy tool for cutting metal. It can be used to cut pipe and bar, but it’s most effective when you need the smaller lengths of sheet aluminum that this saw has been designed primarily around; fortunately, there are other blades available as needed should those not work out well enough or if they wear down quickly over time – just make sure whatever material gets cut will fit through your desired size!

CNC Machine

All of the methods mentioned above work best with initial sectioning, cutting aluminum sheet metal, or bar stock into more manageable pieces. For finer, more detailed work, CNC machine tools provide some of the best options. CNC lathes and mills turn larger workpieces into finished tools and can be used to create entire production runs of identical parts.

Aluminum Cutting Tips and Tricks

When sectioning aluminum, remember these tips – they’ll make your job a lot easier.

Woodworking tools will work

Aluminum is one of the softer metals. If you’re using high-quality tools for woodworking, like table saws and circular saws, they will probably work to cut aluminum as well. Repurpose some of your wood cutting tools.

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Use lubricant

Metal-cutting lubricants help to reduce chatter and inconsistencies during the cut, and can also help to remove swarf and chips. The most common lubricant for aluminum is WD-40; others include metal cutting wax and even jets of water applied to the blade.

Smaller diameter blades are better

Smaller blades produce cleaner, more accurate cuts. There’s a fine line here, of course – go too thin, and you risk breaking a blade. Too small, and you may not be able to cut through larger workpieces. But don’t assume that the larger, thicker, more aggressive saw blades will necessarily produce a better cut.

clamping when cutting aluminumClamp, clamp, clamp

Clamp your workpiece down for better results. Stability is key – the more stable the workpiece, the more accurate the cut will be and the better the final result. Clamping your workpiece also improves safety; there’s less chance of something flying off the saw and harming the operator.

Wear protection

Always wear adequate protective equipment when cutting aluminum or any other material. That means safety glasses or safety goggles as well as hearing protectors. Full face shields might also be advisable.

Have the correct hand tools

Tin snips and shears, angle grinders, chisels, carbide blades – these are all the tools of a craftsman. Or even of an ordinary handyman tackling a bunch of DIY projects. In both cases, be sure you’ve got the right range of hand tools to complement your saws or machine tools.

Example: 4 simple steps to cut aluminum with a circular saw

Ready for the simple process? Follow these steps to cut aluminum sheet metal or bar stock.

Set it up correctly

Circular saws require clearance beneath the workpiece. If you’re clamping your aluminum sheet to a sawhorse, be sure you’ve got enough clearance to cut close to the stand without cutting into it. A good setup also requires that you think about how large the blade is, where it will travel, and if it’s thick enough to give a clean cut.

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Lay out and measure your cut

If you’re using a CNC machine, this step is required – you’ll need to program the machine with the exact cuts in the operation. If you’re simply cutting off a piece of bar stock, this is almost unnecessary. For everything in between, be sure to outline or draw out your cuts so you exactly what to do and in the correct order. Circular saws are usually hand-held; don’t try to freestyle your cut – draw it out on the workpiece, and then you’ll have something to follow.

Lubricate the blade

WD-40, water, cutting wax – whatever you use, now’s the time to lubricate your blade. Good lubricant reduces friction, makes for a cleaner cut, and keeps both blade and workpiece from overheating.

Keep your blade perpendicular to the workpiece. Angled cuts are thicker – there’s more material to be cut – which can lead to distorted or warped cuts as well as jagged and uneven edges

Clamp the workpiece

High-quality, cast-iron c-clamps are a great way to lock your aluminum workpiece into place. Use more than one clamp along the path of travel of the blade so that the workpiece doesn’t “walk” away from the blade during sectioning.

Also, consider the waste – the piece you’re cutting off. Aluminum can be heavy and freshly-cut aluminum can be quite sharp. You may want to clamp the excess in place.

Looking for even more ways to cut aluminum? This video includes a few that aren’t on this list, so feel free to check it out.

About Peter Jacobs

Peter Jacobs is the Senior Director of Marketing at CNC Masters, a leading supplier of CNC mills, milling machines, and CNC lathes. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general. You can connect with him on his LinkedIn.

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