Kerf Width Explained
Here’s an example on how to measure for cuts taking the kerf of the blade into account.
Let’s say you have a baseball bat that’s 30 inches long. You want to cut the bat in half, so you end up with a 15-inch barrel (the thick half) and a 15-inch handle (the thin half). You cut the bat in half with your saw. It looks great! You cut the bat right in the middle. Now you have the thin handle and the thicker barrel that are the same length.
Now you measure both to make sure they are both an equal 15” long. But they’re not. Both are a bit shorter than 15” now. Both are the same length of 14- 15/16”- a touch shorter than 15 inches. The reason for this is the kerf of the saw blade was 1/8 of an inch. The kerf is the width of the saw blade and the amount of material removed during a cut.
The saw blade removed 1/8 of an inch of wood when it was making the cut. Divide the 1/8″ in half to determine how much extra wood was removed each half of the bat, that is 1/16″ on each side. That is why both halves of the bat are 14- 15/16 inches and not 15 inches. The saw blade didn’t just cut the bat in half- it removed all the wood in the path of the saw blade. The width of the material removed is called the kerf.