Rip vs Crosscut Teeth

If a saw feels like hard work, or leaves a torn edge, or seems to fight you, the most likely explanation is not that it is dull or cheap. It is that the teeth are filed for the other kind of cut.

The two kinds of cutting

Wood is a bundle of long fibers running the length of the board. Cutting along those fibers and cutting across them are physically different problems, and they want differently shaped teeth.

Ripping— cutting along the grain — means separating fibers from each other lengthwise. You are not severing anything; you are splitting between fibers and chiselling out the waste. So rip teeth are filed straight across, like a row of tiny chisels, and they cut on their leading edge.

Crosscutting— cutting across the grain — means severing every fiber. If you tried it with a chisel-shaped tooth the fibers would tear and lift rather than part cleanly. So crosscut teeth are filed at an angle, producing knife-like points that score the fibers on either side of the kerf before the waste between them is removed.

What happens when you use the wrong one

A crosscut saw ripping. Slow and hard work. The knife points are not shaped to lift waste along the grain, so you saw and saw and remove very little. People conclude the saw is dull.

A rip saw crosscutting. Fast, and it leaves a torn, ragged edge with fibers lifted on the exit side. The chisel-shaped teeth are tearing fibers rather than severing them. People conclude the saw is coarse or badly made.

Neither is a quality problem. Both are the wrong tool, and both are extremely common because almost nothing at the hardware store tells you which filing you are buying.

How to tell which you have

Look along the teeth from the end of the saw. Rip teeth are square across the plate; each tooth face is perpendicular to the blade and you see a flat chisel edge. Crosscut teeth are filed at an angle, and you can see alternating bevels leaning left and right along the row.

If you cannot see it clearly, run a fingertip carefully along the side of the teeth: crosscut teeth feel like a row of tiny points, rip teeth feel like a row of tiny flats.

Set, while we are here

Teeth are also bent slightly alternately left and right — the set. This makes the kerf slightly wider than the plate, so the plate does not bind in its own cut. More set means an easier but wider cut; less set means a narrower, cleaner cut and more risk of binding.

Fine joinery saws have very little set. Flush-cut saws have none at all, which is what lets the plate lie flat on a surface without scratching it.

The two useful answers

A ryoba. Rip teeth on one edge, crosscut on the other. The problem stops existing, which is why it tops the main saw roundup.

A universal or hardpoint saw.Modern western saws are frequently filed with a compromise geometry that does both adequately. It is genuinely a compromise — worse than a dedicated rip saw at ripping and worse than a dedicated crosscut at crosscutting — and for a saw that lives in a toolbox it is the right compromise.

The one place to be deliberate is joinery. A tenon shoulder is a crosscut and a tenon cheek is a rip, and having the right filing for each is a genuine improvement in the finished joint.