Before long, your home renovation or repair will involve calculating, marking and cutting angles. Whether you have a fancy trim saw or the old standby circular saw, you’ll save wood and frustration if you measure and mark angles right the first time.
For simple 45 degree miters, you can use a combination square. This consists of a metal rule attached to a headpiece that slides along the rule. You tighten it in place where you want it and position the 45 degree edge of the headpiece on the edge of the wood to draw your line.
You can do the same thing with a speed square (which is actually a triangle). By positioning the raised edge against the board, you can easily mark a 45 degree angle, and even use the edge of the square as a guide for your circular saw’s baseplate.
The speed square also has degrees marked along the long side so you can measure existing angles and transfer them to your next cut. Add a handy attachment called a layout bar, and you have a fancy carpenter’s square to mark cuts on rafters or stair rise and run on stringers. Adjust the layout bar to the correct angle, then simply slide it along and trace your cuts.
But one of the handiest tools to have is a bevel gauge or adjustable T-bevel. This is a simple little device that looks something like a jack knife, with a metal blade that you can lock at any angle from 0 to 180 degrees. Just take your angle from either a protractor or an existing angle, lock the blade in place, and transfer it to your stock — no careful calculations or geometry to worry about.