Monarch Metal How-To: Cutting Aluminum on the Job Site


In an ideal world, aluminum would be cut by a fabricator who has the tools and experience to make clean, low-cost cuts. But sometimes, cutting aluminum to size needs to be held off until measurements are taken at the job site, which means it’s up to you and your team to tackle this task.

Luckily, aluminum is a lightweight, soft metal that’s relatively easy to cut–given that you’ve got all the appropriate tools onsite, of course. And if you know your way around those tools, then that makes the job much easier. Even still, adding this extra step to the project at hand will cost you time, money, and work site progress.

To eliminate some of the hassle from making cuts on the job site, we’ll go over the process step-by-step. Here’s what you’ll need to get the job done:

  • Lubricant, like beeswax or paraffin wax
  • A power saw, like a chop saw, circular saw, or table saw
  • Carbide blade
  • Saw horses (if using a circular saw)
  • Clamps
  • Safety equipment (see Step 1)

Step 1: Safety

640px-Chainsaw_helmetWhen you’re taking stock of all your cutting tools and materials, please make sure that your safety equipment is also on your list. For cutting aluminum, you will need:

  • Ear plugs
  • Work gloves
  • Eye and face protection
  • Respiratory protection

While each item on this short list can help you avoid serious injury, it’s essential to use caution and your best judgment when cutting any job site materials. So, make sure you’re alert and completely comfortable with the task before attempting to make any cuts.

Step 2: Preparation

Woodworking tools like chop saws, table saws, and circular saws work at speeds that are often too fast for aluminum, which makes it necessary to both lubricate the blade and reduce its speed. This will help you avoid kickback. Speeds between 750 FPM and 1,500 FPM are recommended, depending on the alloy.

Reducing a blade’s speed is simply a matter of reducing its diameter. So, if you’re using a 10” table saw, you can swap out the blade for one that’s a bit smaller–say, 7 ¼”. It’s best to use a carbide blade with narrow kerfs because it minimizes the amount of wasted material. And since aluminum is lightweight, clamping it to a piece of timber is recommended to avoid movement while cutting.

The next step after choosing the appropriate blade is to lubricate it. Beeswax or paraffin wax are recommended, as these help keep the blade from welding to the aluminum while cutting.

Step 3: Making the Cut

saws-58578_640First thing’s first: never stand in the kickback zone. Whether you’re cutting aluminum or some other type of material on the job site, there is always potential for kickback, so make sure you’re aware of your positioning while making the cut.

Most metal cutting pros recommend using a chop saw with an aluminum blade, as it produces a very smooth cut that eliminates the need to trim the edges. But if a chop saw isn’t available, there are some other options:

  • If a circular saw happens to be what you have, then it’s best to use saw horses so you can make as clean and easy a cut as possible.
  • For a table saw, the table itself should be sufficient enough to hold the aluminum. When you’re all set up to make the cut, simply feed the aluminum through the blade as slowly as possible. You’ll want to move even slower than you would if you were cutting a piece of wood.
  • Metal cutting router bits can also be used to cut and shape aluminum. With these, you’ll definitely want to be somewhat generous when applying lubricant, otherwise you’ll be left with an aluminum-clogged cutter. When using a router, make sure you clamp the aluminum firmly in place.
  • If you need to make circular cuts, a jig saw or a circular saw work best. Just remember that with a circular saw, you’ll be making pretty rough cuts, so edge trimming will be necessary.

Step 4: Trimming the Edges
After making your cuts, you’ll likely be left with more than a few rough edges. To smoothen or straighten these out, you can use a couple of tools. If you’re looking to keep the process quick and simple, a standard file works just fine. You can also use a sharp deburring tool or Scotch-brite pad to work on small pieces.

But when working with larger cuts, a deburring wheel will come in handy. Another option is the Arbortech Mini Carver. This is an attachment for a 4” angle grinder that can be fitted with a carbide tooth blade and used to quickly trim aluminum edges.