How to Use A Miter Box To Cut Trim

When installing decorative trim in your home, part of the job is cutting the trim to turn corners. To turn a 90-degree corner you must cut the two adjoining pieces of trim each at a 45-degree angle. To ensure an accurate cut, use a miter box and a back saw. A miter box is a open-top U-shaped box with saw guides on the sides for both left and right 45-degree cuts, as well as a straight 90-degree cut. Using the miter box as a guide when making your cuts ensures that trim is always cut to a precise and uniform angle.

Things You'll Need

  • Tape measure

  • Pencil

Step 1

Measure the length of the trim needed, then mark the trim using a pencil.

Step 2

Determine whether you will be making a 45-degree left, 45-degree right or 90-degree, or straight, cut.

Step 3

Align the trim with the two guide slots for the appropriate degree and direction cut.

Step 4

Insert the back saw into the guide slots, then lower the blade to the trim to align the blade with the trim.

Step 5

Use deliberate and steady passes with the saw to cut the trim.

Tip

If you are unsure if a left or right cut is needed for the particular piece of trim that you are using, make test cuts using scrap pieces of trim.

References & Resources