Everyone knows a blunt blade cuts badly. The cost that gets missed is what it does to everything around it.
To the wood
Burning, a fuzzy edge, and tear-out on the underside. Every one of those is remedial work: sanding, a trimming pass, sometimes a remade part.
To the machine
A rubbing blade needs more feed force, and that force goes into the arbor and its bearings as a side load they were not sized for. The motor draws more current, runs hotter, and on a portable tool that is exactly how a thermal cutout starts tripping. Belts slip more. On a table saw the extra effort is also the ingredient kickback needs.
To the blade itself
This is the one that surprises people. Heat is what destroys carbide and destroys the body tensioning. A blade pushed well past dull gets hot enough to micro-crack the carbide and to blue the plate. At that point it cannot be sharpened back to what it was, so the money saved by delaying a regrind buys you a new blade instead.
To you
More force, closer to a spinning blade, on a cut that is fighting back.
The rule is simple: send a blade for sharpening while it is only just going off, not when it has stopped working.
Dull, or just dirty?
Before sending a blade off, clean it. Resin and pitch baked onto the teeth and the plate make a sharp blade burn and drag exactly like a dull one. Soak it in a blade cleaner, scrub the gullets with a brass brush, and make a test cut. If it still burns, look at the tips under a light: rounded corners, a shiny flat on the cutting edge or a chipped tip mean it is genuinely dull.
Sharpen or replace?
A good carbide blade can be resharpened several times by a saw shop, usually for a fraction of its price, until the carbide tips are too small or one is missing. An inexpensive blade often costs about the same to replace as to sharpen; for those, replacement is the honest answer. Either way, a clean, sharp blade is safer than a dull one pushed harder.
The blades we compare are on the saw blades shelf; for choosing one, see choosing a saw blade for the material.
Last reviewed October 27, 2026