What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
Choosing a blade for aluminum extrusions is not the same as choosing one for steel or ordinary construction lumber. Aluminum is soft, but it is also sticky. A poor blade can load up with metal, grab the workpiece, leave a rough burr, or overheat the cut in seconds. The right choice depends on the extrusion’s wall thickness, the saw you own, the finish you need, and how many cuts you expect to make.
Start With the Saw
First match the blade to the saw, not the other way around. A miter saw, table saw, circular saw, and metal-cutting chop saw use different blade diameters, arbor sizes, and operating speeds. Never install a blade whose maximum RPM is lower than the saw’s no-load speed.
For a typical 10-inch miter saw, that usually means a 10-inch blade with a 5/8-inch arbor. A 12-inch saw commonly uses a 1-inch arbor, though you must verify your particular tool. A standard wood-cutting circular saw may run too fast for some aluminum blades, while a dedicated metal-cutting saw may run at a lower, more suitable speed.
Check the blade packaging for approval for non-ferrous metals. “Carbide-tipped” by itself is not enough. Many general-purpose wood blades use carbide but have tooth geometry and hook angles that make them unsafe or unpleasant in aluminum.
Choose Tooth Count for Wall Thickness
Tooth count is the first major buying decision. The general rule is that at least two teeth, and preferably three to four teeth, should remain in the material throughout the cut. Too few teeth can cause grabbing and chipping. Too many teeth can rub instead of cut, producing heat and clogging.
| Aluminum workpiece | Useful blade range | What to expect |
|---|---|---|
| Thin sheet or very thin-wall tubing | 80–120 teeth on a 10-inch blade | Clean entry and fewer tooth marks, but slower feed and more clogging risk |
| Common architectural extrusion, about 1/16 to 1/8 inch wall | 80–100 teeth on a 10-inch blade | Good balance of finish, speed, and tooth engagement |
| Thick-wall extrusion or solid aluminum bar | 60–80 teeth on a 10-inch blade | Better chip clearance and less rubbing than a very high-count blade |
| Rough cuts where finish is unimportant | 40–60 teeth on a 10-inch blade | Faster cutting, but more burrs and a greater chance of grabbing |
These are starting points, not a substitute for checking the blade manufacturer’s chart. Tooth count does not scale directly between diameters: a 7-1/4-inch blade with 60 teeth is much finer than a 12-inch blade with 60 teeth.
Look for Non-Ferrous Blade Geometry
A proper aluminum blade normally has carbide teeth with a triple-chip grind or another geometry specifically intended for non-ferrous metals. The teeth often have a shallow or negative hook angle. That makes the blade less aggressive than a typical wood blade and reduces self-feeding and grabbing.
Negative hook blades require a controlled feed, but they are easier to manage when cutting thin extrusions. A high-positive-hook wood blade can pull the work into the blade, especially if the extrusion twists or is not clamped. That is a failure mode worth taking seriously: aluminum is light enough to move suddenly, and a long extrusion can act like a lever.
Look for carbide designed to resist aluminum buildup and a blade described as suitable for aluminum, brass, copper, or other non-ferrous metals. A polished or nonstick coating can help, but coating is secondary to tooth shape and the correct tooth count. If you are comparing options, start with blades made for non-ferrous metal, then narrow the choice by diameter and arbor.
Balance Kerf, Finish, and Cutting Speed
Full-kerf blades remove more material and generally run more smoothly, but they need a saw with enough power and a rigid setup. Thin-kerf blades waste less aluminum and can be useful on a lower-powered saw, but they may deflect more easily. Deflection is especially visible on long, narrow extrusions, where the cut can end up out of square.
For visible frame parts, a high-quality 80- to 100-tooth aluminum blade is usually worth the additional cost. It leaves a cleaner edge and reduces filing. For brackets, hidden parts, or a one-time project, a cheaper carbide non-ferrous blade can be perfectly adequate. You may spend a few extra minutes deburring, but there is little value in buying a premium blade for six rough cuts.
Do not judge a blade solely by its advertised tooth count. A poorly sharpened 100-tooth blade can cut worse than a well-made 80-tooth blade. Clean side clearance, flat tooth tips, and consistent carbide brazing matter more than a large number printed on the label.
Use Lubrication and Control the Chips
Aluminum chips can weld themselves to the carbide teeth. Once buildup starts, the blade cuts less efficiently, heats up, and may leave a rough, smeared edge. A dry cut can work for a few small extrusions, but light lubrication improves consistency.
Use a purpose-made aluminum cutting lubricant, wax stick, or a small amount of compatible cutting fluid applied according to the blade and saw instructions. Do not flood a standard electric saw unless it is designed for wet cutting. Keep liquid away from the motor and electrical controls. A dry lubricant or wax is often the safer choice for a miter saw.
For frequent work, a lubricant made for aluminum cutting costs little compared with replacing a clogged blade. Vacuum or brush away chips after the blade stops; compressed air can spread sharp chips into bearings, eyes, and nearby surfaces.
Set Up the Cut Correctly
Support the extrusion on both sides of the blade. Long unsupported stock can lift, rotate, or pinch the blade as the cut closes. Clamp the workpiece firmly, but avoid crushing thin walls. If the extrusion has a finished face, place it where the blade’s exit-side chipping will be least visible, or use painter’s tape to reduce surface marking.
Let the blade reach full speed before entering the material. Feed steadily without forcing it. If the motor slows sharply, the cut is too aggressive, the blade is dull, or the tooth count is too high for the wall thickness. If the blade squeals and produces powder rather than chips, it is likely rubbing or clogged.
When Another Tool Is Better
A circular saw aluminum blade is practical for long straight cuts in sheet or large extrusion, but it demands especially careful clamping and chip control. A band saw is slower but safer for irregular profiles and thick stock. An abrasive cutoff wheel is usually the wrong choice for aluminum: it loads quickly, creates heat, and leaves a rough, heavily burred edge.
For occasional DIY work, buy the correct non-ferrous carbide blade for your existing saw, clamp the extrusion, and accept a little deburring. For production cutting or repeated visible joints, spend more on a durable, fine-finish blade and a rigid saw setup. The blade only performs as well as the support underneath it.