Metal

Aluminium is soft, and that is precisely the problem. A saw that is designed for hard materials will rub rather than cut, the chip welds to the wire, and the cut stalls. Aluminium is also the material where diamond wire is most often tried and abandoned for the wrong reason: the wire was correct, the parameters were not.

What actually goes wrong when cutting aluminium

Three failure modes account for most of it. First, loading — soft chip smears across the diamond layer, the wire stops cutting and starts burnishing. Second, thermal growth — aluminium expands roughly twice as much as steel over the same temperature rise, so a part that measures correctly during the cut can be undersize when it cools. Third, burr — a dull wire pushes metal instead of shearing it, and the burr on the exit face can be heavier than the kerf itself.

All three are solved by the same thing: a coarse, open diamond layer, high wire speed, and enough coolant to carry the chip away before it can weld.

Where diamond wire beats the alternatives

• Band saw — cheaper per cut on bar stock, but blade life collapses on thick plate and the cut needs a second operation to clean up.
• Circular saw — fast, but the kerf is wide and thin-wall extrusions distort.
• Waterjet — excellent edge, but abrasive consumption and taper on thick sections add up, and the garnet has to be disposed of.
• Diamond wire — narrow kerf, no distortion on thin wall, and the same wire that cuts the aluminium will cut the steel insert bonded into it without changing setup.

Wire selection for aluminium

Parameters to start from

Run the wire fast — 25–35 m/s is a normal band for aluminium, noticeably faster than for steel — and keep the feed light. The wire should sound like it is cutting, not squealing. Flood the cut with a water-based coolant; mist cooling is not enough to clear aluminium chip. If the wire starts to load, increase speed before you increase feed.

Compensation matters more here than on hard materials. Because aluminium moves with temperature, measure the part after it has returned to room temperature, not at the machine.

Cost per cut

Wire consumption on aluminium is driven by loading rather than by abrasive wear, so a coarse wire that keeps cutting will usually outlast a fine one that keeps stalling. We quote by the square metre of cut and will tell you the expected wire consumption for your section before you commit to a spool.

Test cut

Send a section of your actual alloy — 6061 and 7075 behave differently, and castings behave differently again — and we will return the edge condition, the burr height and the consumption figure rather than an opinion.