Power Saws and Saw Blades

Tooth count, blade size and shank type

A saw is only as useful as its blade, and blades are sold by a handful of numbers. Tooth count, written as T or TPI, sets the cut: fewer, larger teeth cut fast and rough, as on a 24-tooth framing blade, while more teeth cut slowly and cleanly. Diameter must match the saw, such as 7-1/4 inch for many circular saws, and the arbor hole must fit the spindle. Jigsaw and reciprocating blades also need the right shank, because a blade that does not match the saw's clamp will not lock in.

Which blade and saw suit which material

Use the right tool for the stock. Framing and general wood use a coarse carbide-tipped blade; fine trim wants a high tooth count. Demolition blades are made to survive occasional nails, and metal-cutting blades have fine teeth and need slower speeds. A diamond blade cuts masonry and tile and should be used with dust control, such as a shroud that connects to a vacuum. Corded saws give steady power for long cuts, while cordless types add freedom but stop when the battery does.

Questions about Power Saws and Saw Blades

What does TPI mean on a saw blade?

TPI is teeth per inch. Low numbers, around 6 to 10, remove material fast and leave a rough edge, which suits demolition and rough lumber. Higher numbers, 14 and up, cut slower and smoother, which suits metal, plastics and finish work.

How do I know if a blade fits my circular saw?

Match the diameter printed on your saw or in its manual, such as 7-1/4 inch, then check the arbor hole size and that the blade's maximum RPM is above the saw's no-load speed. Never use a larger blade than the saw's guard allows.

Can I use a diamond blade to cut wood?

No. Diamond blades grind rather than cut and are made for masonry, tile, concrete and stone. Used on wood they clog and burn, and they can kick back. Choose a toothed carbide blade for wood, and use dust control with any diamond blade.