What Is a Compound Miter Saw and How Do I Use One?

Are you working on a project that requires multiple precise, angled cuts? The handy compound miter saw is a versatile power tool that will make the job faster and easier.

What is a compound miter saw?

A compound miter saw is a type of miter saw commonly used in carpentry and woodworking for cutting molding, framing and trim. It features a circular blade that spins vertically on a swing arm and can be adjusted and tilted to make angled cuts. This saw is ideal for crosscuts, miter cuts and bevel cuts in a variety of materials such as laminate flooring, dimensional lumber and trim board.

Compound miter saw vs. miter saw

A standard miter saw is useful if your project requires crosscuts and miters but not bevel cuts. A compound miter saw allows you to make miters and bevel cuts simultaneously, producing angled bevels. This “compound” benefit results in perfectly angled edges and joints such as those needed in baseboards.

Compound miter saw vs. chop saw

Don’t confuse the compound miter saw with the similar-looking chop saw. The chop saw uses a larger, stronger, fast-rotating abrasive cutting wheel or toothed blade mounted on a rectangular stand. The wheel or blade, which is fixed, moves up and down in a chopping fashion to make straight cuts in metal, tile, concrete and other tough materials. The chop saw can’t cut angles or bevels, so it is best suited for making straight, rough cuts.

Compound miter saw uses

With a compound miter saw, you can make many of the cuts you need in common carpentry, cabinetry and building projects. Here are some examples:

• Crosscuts for framing studs 

• Crosscuts and miters for floorboards

• Miters and bevel cuts for window and door trim

• Bevel cuts for baseboards, crown moldings and picture frames

Not sure what cut you need to make? Brush up on the three main types of cut.

What is a miter cut?

A miter is an angled cut (other than 90 degrees) across the width of a board. Miter cuts of 45 degrees are typical for window trim.   

What is a bevel cut?

A bevel cut slopes through the thickness of your board at an angle from top to bottom. A bevel cut is best for any project that requires angles in two planes, such as a picture frame.   

What is a crosscut?

A crosscut is a straight cut across the wood grain of a board to achieve the desired board length. Crosscuts are often used to create even lengths of framing lumber.

How to use a compound miter saw

Every model of saw is different, so consult the manual for usage and safety instructions. Here’s a general overview of how to use a compound miter saw.

1. Set the saw on a stable surface, such as a workbench or table, and secure it with one or more clamps. Use saw horses or another table to support long pieces of wood.

2. Unlock the blade and plug in the saw.

3. Position the blade. For a miter cut, use the lever on the saw base to swivel the blade arm to the desired angle of your cut. Tilt the saw blade from left to right for a bevel cut to achieve angles up to 45 degrees. If you use a single bevel saw, the blade tilts only one way, so you will need to flip your board over to make cuts in the opposite direction. For a crosscut, position the blade at a 90-degree angle to the surface of your material.        

4. Measure and mark your material with a light pencil line. Remember the adage, “measure twice, cut once.”

5. Push your board against the saw’s fence (the metal backrest secured to the base of the saw) to ensure an accurate cut.

6. Touch the blade to the material, aligned at the waste side of your mark. 

7. Bring the blade up to speed and slowly bring it down through the material, from front to back.

8. When you’re finished cutting, turn off the saw and let the blade come to a complete stop before removing your cut piece.

9. Lock the blade for storage and transport.

Hints on blade size and teeth 

The size of the blade is an important consideration. Blade sizes range from 8 inches to 12 inches. A 12-inch compound miter saw will cut wider, thicker boards than a smaller blade. On the other hand, it’s easier to make accurate cuts on smaller pieces with a 10-inch compound miter saw blade.

Also consider the number of saw teeth you need based on the type of cut you plan to make. More teeth will result in a slower, finer cut. A blade with fewer teeth will deliver a faster, rougher cut. 

Compound miter saw safety

Safety is essential when working with any power tool. Heed these safety tips before you start the saw and while you’re using it.

• Read the owner’s manual to understand the proper, safe use of the saw, and follow the instructions.

• Wear safety goggles and earplugs.

• Don’t wear gloves, since they can easily catch on a spinning saw blade. 

• Don a dust mask to protect your lungs from small particles. 

• Wear close-fitting clothing and remove any jewelry.

• Keep your hands at least 6 inches from an active blade.

• Stay focused while operating the saw.

• Remember to lock the blade when you’re finished. 

If you find yourself working on a job with a lot of transition pieces that require compound cuts with angles and bevels, look no further than the compound miter saw. It’s a useful multi-purpose saw for making not only miters, bevels and crosscuts but also any finer cuts you need to add finishing touches to your project.

Visit our online marketplace to browse our selection of saws or stop by your local United Rentals branch.