Design & DIY

How to choose the right mitre saw

A mitre saw is the fastest way to become an apparent genius at cutting trim and construction lumber accurately. Sometimes called a chopsaw, these saws make precise angled crosscuts. They’re especially useful for repeating the same angled cut—quickly and accurately. Though all models are similar, there are three main types to choose from.

Simple mitre saws have a blade-and-motor assembly that pivots down into the wood to make each cut. The wood is supported on a table that rotates one way or the other for angled cuts. A 10″-blade saw can make a 90° crosscut through a 2×6; a 12″ can handle a 2×8. These simple saws were once common, but fewer manufacturers produce them these days.

Get one if:

  • Money’s tight
  • You need a lightweight saw you can lug around easily.
  • You make vertical cuts only (no compound angles).
  • You usually cut 2x6s or smaller.

Compound mitre saws, like simple mitre saws, pivot downwards to complete a cut—but the blade and motor can also be tilted away from vertical at a range of angles. This capability allows angle control in two directions, so you can cut compound angles. These saws cut the same widths of lumber as simple mitre saws.

Get one if:

  • Slightly more weight and higher price are okay.
  • You’re working on trim, roof framing, or other projects where crosscutting wood at two angles is essential.

Sliding compound mitre saws set the blade-and-motor assembly on rails or an articulated arm, so it can move back and forth, as well as tilt from side to side and pivot downwards to make cuts. The sliding action allows 90º crosscutting of wood as wide as 12″, making this mitre saws the most versatile. But there’s a trade-off for this range of motion: More parts that move can mean cuts that are less precise.

Get one if:

  • You’re often cutting wide boards.
  • Weight and cost are non-issues.
  • You’re okay with slightly rougher, less accurate cuts than other mitre saws provide.

How to test your mitre saw

Mitre saw markings show 45°, 90°, and other angles. Don’t always trust them. Test by making a 90° vertical cut in a straight 1×3 or 1×4. Flip the off-cut, then butt the cut ends, with edges of both pieces tight to the fence. If there’s a gap where the ends meet, that angle is twice the saw’s error. Different saws are adjusted differently (check your manual)—once you fine-tune a 90° cut, all other side-to-side angles will be correct. On compound saws, repeat the test to ensure the blade is precisely vertical. If the 45° corners of your trim still don’t fit tightly, blame that old door frame or window jamb and make your cut a little off square to compensate for the usual cottage wonkiness.

Ready to get started with your mitre saw? Here are few projects to try:

Make a shadowbox
Make a hockey stick coat rack