Aluminium extrusion is easy to cut with tools you probably already own — but the difference between a clean, square cut and a ragged, burred one comes down to blade, technique and a little lubricant. Here's how to do it properly, and when it's worth letting us cut it for you.
The right saw
A standard drop saw (mitre saw) is ideal — the same saw you'd use for timber. A chop saw or a fine-tooth hand mitre box also works for smaller sections. What matters most isn't the saw; it's the blade.
The right blade
This is where most rough cuts come from. Use a sharp, fine-tooth blade:
- A TCT (tungsten carbide tipped) blade with a high tooth count gives the cleanest result. Blades sold for aluminium or non-ferrous metal are ideal, but a sharp fine-tooth wood blade cuts aluminium well too.
- More teeth = finer finish. A high-tooth-count blade leaves less burr and a smoother face.
- Sharp matters. A worn blade grabs, chatters and leaves a torn edge. If your cuts are rough, the blade is usually the culprit.
Lubricate the cut
Aluminium is soft and can clog or weld to the blade if cut dry, which tears the finish. A little lubricant fixes it: light oil, CRC or kerosene, applied to the blade or cut line. It keeps the cut clean, protects the blade and stops the swarf sticking.
Technique
- Clamp the extrusion firmly. It must not move or vibrate. Support long lengths so they don't pinch the blade.
- Mark your length and line up the cut.
- Let the saw reach full speed before it touches the metal.
- Feed steadily, don't force it. Let the blade do the work — pushing too hard tears the edge and loads the motor.
- Deburr the ends. A quick pass with a file or deburring tool cleans the cut edges and clears any swarf from the slots so hardware still slides freely.
Safety
Aluminium swarf is sharp and the chips fly. Wear eye protection and gloves, keep hands clear of the blade, and clean chips out of the slots before assembly.
Accuracy you can expect
Cutting by hand, a careful setup will get you within a millimetre or so — fine for most framing. Where you need repeatable precision — every member identical, square ends, tight tolerances — that's harder to hit consistently with a hand setup.
Or let us cut it to length
If you'd rather skip the saw — or you need accuracy — we cut to length for you. Order the exact lengths you need and we cut to +/- 0.5 mm (for lengths 100–3000 mm), with clean, square ends, every piece in a batch identical. It's available across the range — extrusion, flat bar, round tube, angle and more — just select Custom Cut Length on the product and enter your sizes.
That means no full bars to store, no offcuts to dispose of, and frame members that arrive ready to assemble — made in New Zealand and cut to your spec.
Got an awkward cutting job or a long list of lengths? Talk to us — it's often faster and tidier to have it cut here.