Guide to Cutting Aluminum with a Circular Saw

Published by Ted on Jun 26th 2019

 Cutting Aluminum

Most grades of aluminum offer excellent work ability and weldability, making them suitable for a wide range of applications. The preferred way to cut this material is with a miter saw but a circular saw still works. When a circular saw is your only option, follow these steps to safely cut through aluminum sheets or plates.

Choosing the Right Blade for Cutting Aluminum

Standard woodworking blades with carbide tips still work but require extra precautions. The tips are more likely to grab the aluminum or break off. Almost all major blade manufacturers make blades specially designed for cutting non-ferrous material. In fact, most companies have special grades of carbide for cutting aluminum alloy.

When comparing options, look at the tooth count of the blades. Thicker material requires fewer teeth while more teeth help deliver smooth cuts on thinner aluminum.If the aluminum is less than 1/16-inch thick, use a blade with more than 10 teeth per diameter inch. For example, several companies produce blades with 200 teeth specifically for cutting very thin aluminum.

When cutting material up to 1/8-inch thick, use a blade with 10 teeth per inch, such as a 10-inch x 100 tooth or 12-inch x 120 tooth blade.For material up to 1/4-inch thick, use eight teeth per inch. For thicker sheets of aluminum, use a blade with just six teeth per diameter inch.

Lubricate the Blade for Additional Protection

The biggest risk of cutting aluminum with a circular saw is the blade grabbing the material.If the blade catches on the material, you risk injury. People have lost fingers because of this issue.No matter the type of blade, use lubrication to keep the blade from gumming up with debris or catching on the material. The lubrication also protects the blade and prevents overheating, reducing the risk of chipped tips.

The easiest way to apply lubrication is with a saw blade wax stick. These sticks include specially formulated ingredients to help produce smoother, quicker cuts. You simply rub the stick across the teeth of the blade. WD-40 also works for lubricating the blades. However, you may need to apply the oil multiple times. Compared to saw blade wax sticks, WD-40 does not keep the blade lubricated as long.

Always Clamp the Material and Wear Protection

After choosing the right blade and lubrication, you need to secure the aluminum. A miter saw clamps down the material as you cut while a circular saw can pull.To keep the material secure, use multiple clamps. 

At least two industrial C-clamps should suffice. Look for heavy-duty cast iron clamps for a firm hold on the aluminum sheets or plates.Do not wear gloves when working with a circular saw. The blade of the guide rail may snag the glove.

Besides gloves, avoid loose-fitting clothing and take off jewelry and rings. You do not want anything catching on the blade. However, you should wear eye protection.

Always wear safety glasses or a face shield when cutting metal, including very thin aluminum. While lubrication helps protect the blades from overheating and chipping, accidents can happen.

If you wear safety glasses instead of a face shield, wear a mask. Masks and shields keep you from breathing in debris while cutting.

Summary

Cutting aluminum with a circular saw requires a few special steps. Ensure that you have the right blade. A carbide blade works but is more likely to grab the material.If possible, purchase a blade specially designed for cutting aluminum and other non-ferrous materials.

Always use lubrication even when using a blade designed for cutting aluminum.Before cutting, clamp the material to the worktable. You should also wear a face shield.With these precautions in place, you should have no problem cutting aluminum with a circular saw.