What blade do I need for cutting aluminium extrusion?

For extrusion and other wrought sections a bi-metal blade is the usual choice. Go as coarse as the section allows so the gummy swarf clears, but not so coarse that teeth straddle a thin wall and snatch. A steady feed matters as much as the blade: teeth that rub rather than bite load up quickly in aluminium.

What blade should I use for cast aluminium?

Castings are harder on blades than the alloy alone suggests. High-silicon casting alloys and any residual sand wear an ordinary edge quickly, so use a foundry-pattern blade: bi-metal for general non-ferrous casting work and set carbide where the material is heavily abrasive or you are cropping gates and risers all day.

Why does my bandsaw blade clog when cutting aluminium?

Clogging almost always means the pitch is too fine for the section, so each gullet fills before it leaves the cut. Swap to a coarser blade, feed positively so the teeth bite rather than rub and use lubricant if your machine supports it. Once swarf has welded to the teeth, clean the blade before you carry on cutting.

Material guide

Bandsaw blades for aluminium

Aluminium cuts fast but packs gullets and wears edges. The answer is a foundry-pattern blade at the coarsest pitch the section allows: bi-metal such as Bahco's Sandflex Cobra Foundry for general non-ferrous work and set carbide where high-silicon castings grind HSS teeth away.

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The problem with cutting aluminium

Aluminium is soft. That is the trap. A fine-pitch blade meant for steel puts too many teeth in the cut, each taking a sliver too small to clear. The soft, gummy swarf packs the gullets, sticks to the tooth faces and starts to weld on. Once the gullets are full the blade stops cutting and starts rubbing, the cut heats up, the finish tears and the band wanders off line.

Cast aluminium brings the opposite problem. High-silicon casting alloys carry hard particles that scrub the tooth edge like sandpaper, while foundry work adds sand inclusions and the interrupted cuts of gates and risers. An ordinary edge dulls fast in that company. A dull tooth in gummy material loads up even faster, so the two failure modes feed each other.

The right blade answers both. A coarse pitch gives each tooth a big gullet, so the swarf curls, clears and drops instead of packing. Foundry-pattern edges, whether M42 bi-metal or set tungsten carbide, keep cutting through abrasive material long after a plain edge has gone blunt.

Recommended blades for aluminium

Constructions and ranges from the manufacturers' published data, with the honest reason each blade makes the list. Every one is welded to your machine's length.

Recommended blades for aluminium, drawn from the manufacturers' published ranges. Prices are from prices per welded loop, ex VAT, at the narrowest width and shortest length.
Blade	Construction	Width range	Why this blade	From price
Sandflex Cobra Foundry Bandsaw BladeBahco 3851	HSS tooth edge welded to a flexible alloy steel backingBi-Metal Blades guide	19mm to 41mm	A foundry-pattern bi-metal blade whose M42 tips hold their edge in sandy, abrasive non-ferrous cutting that wears standard teeth quickly.	From £23.50 ex VATsample pricing
Carbide Triple Set Foundry Bandsaw BladeBahco 3869	Tungsten carbide tips on an alloy backing, some further coatedCarbide-Tipped Blades guide	27mm to 54mm	Set tungsten carbide teeth take the abrasive, interrupted cutting of casting work in a blade Bahco rates for aluminium including gates and risers.	From £53.00 ex VATsample pricing
Saw37C Flexback Carbon Bandsaw BladeDakin-Flathers Saw37C	Hardened carbon steel body and teeth, no alloy tipCarbon Steel Blades guide	6mm to 32mm	A hardened carbon tooth edge on a flexible back that cuts aluminium alongside wood and plastics, sensible where blades are changed often.	From £13.00 ex VATsample pricing

Getting the cut right

General rules that hold across machines. Exact widths, pitches and options are on each product page.

Choose a coarse pitch
Aluminium swarf is bulky and sticky, so it needs room. Pick the coarsest pitch your section allows: fewer, bigger teeth mean bigger gullets that carry the swarf out of the cut instead of packing solid. Keep enough teeth in contact with the work to avoid snatching on thin wall sections, but when in doubt go coarser.
Match the edge to the alloy
Wrought and extruded alloys cut cleanly with a bi-metal edge such as the M42 foundry patterns. High-silicon castings and anything carrying sand are a different job: their hard particles grind HSS away, so step up to a set carbide blade before edge wear turns into tooth loading.
Keep the swarf moving
Feed steadily and positively. A tentative feed lets teeth rub rather than bite, which heats the cut and encourages swarf to weld to the tooth faces. Use a chip brush if the machine has one, keep it touching the band and use lubricant where the machine allows: aluminium loads a dry blade far faster than a wet one.
Clamp castings against chatter
Gates, risers and odd-shaped castings give interrupted cuts that hammer the teeth, so clamp the work so it cannot rotate or chatter. Check blade tension and guide condition before the cut: a loose band in soft material wanders. Once a cut runs off line in aluminium it tends to keep going.

Suggested image

Action shot: recommended blade cutting aluminium, cut face visible

materials/aluminium/cutting

Industry guide

Non-Ferrous Metals and Foundry

Cutting aluminium for a living? The industry guide maps the whole workload, not just this material.

Read the guide

Other material guides

Frequently asked questions

Tell the wizard your machine and length and it will match aluminium to a blade that fits.

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