Bevel Basics and Beyond
How a bevel helps you install trim
Woodworkers have used bevels for centuries, and with good reason. This simple hand tool transfers and duplicates angles with dead-on precision. In this article, we'll show you how to set the bevel for angles taken off workpieces, full-sized plans, and written instructions.
If all wall, tabletop, and cabinet corners measured exactly 90°, installing trim moldings would be a snap. You would simply set your saw for a 45° angle and start cutting. Of course, few corners meet this description. Fortunately, with a bevel you can duplicate any angle and transfer it to a sheet of paper. Then, with a few simple procedures you can cut matching mitered trim pieces. Here's how.
First, you need to "bisect" the angle, meaning that you divide the angle into two equal angles. To do this, loosen the bevel's wing nut, lay the body along one edge of the corner, and position the blade along the other edge of the corner as shown above. When the bevel hugs the edges, tighten the wing nut. (You can do the same on inside corners, too.)
Now, align the edge of a sheet of paper with the straightedge of a work surface, and transfer the bevel's angle to the paper as shown below. (You can mark the line using either side of the bevel's blade.)
Bisect angle with a compass
Then, bisect this angle with a compass as in the 4-step drawing below. Here's an explanation of each step:
- Place the point of a compass at the bottom of the marked line (point B), and create points A and C by swinging an arc of any radius between 3" and 5". Use a sharp lead for the best accuracy.
- With the radius of the compass unchanged, place the point at C and swing another arc.
- Move the point of the compass to point A and swing an arc just as you did in Step 2. The intersection of these two arcs creates point D. With a straightedge, draw a line from point B through point D to create the bisect line.
- Adjust your bevel according to the angle between the work-surface edge and the bisect line. To cut a tight-fitting miter, adjust your saw according to the bevel's angle as shown below.
Duplicate cutting angles
When a plan asks for a beveled or angled cut, or angled hole, you can use an inexpensive protractor and bevel for precise results. First, using a protractor, lay out the angle along the edge of a worksheet as shown below.
Then, position the body of the bevel along the edge of the work surface, and set its angle according to the layout line you just drew as shown left. The first few times you try this, it makes sense to double-check the accuracy of your setting by repeating the procedure. This shouldn't take more than a few seconds. Now, use the bevel to set the miter gauge, fence, or table of your tablesaw, radial-arm saw, jointer, drill press, bandsaw disc sander, or other shop tool. If a plan calls for a chamfered edge, and you prefer to do the job with a bench plane, then a bevel can help you in this instance, too. After adjusting your bevel for the necessary angle as described in the previous paragraph, use the bevel to periodically check your work as shown below.
Duplicating angles from full-size drawings
To accomplish this task, lay a straightedge, such as a jointed board, along one side of the angle. Then, place the blade of the bevel against the straightedge, and align the body with the other side of the angle as shown below. This method works more accurately than positioning the bevel above the pattern and eyeballing its alignment without the aid of a straightedge.
If you don't have a bevel (or want to upgrade), consider building the one in our Collector Series of quality-crafted hand tools (below).