Tool Care & Sharpening

Most Dull Tools Aren't Dull

Before you replace a bit or blade, check whether it's actually worn. Pitch and resin build up on carbide and mimic every symptom of a dull edge: burning, increased feed pressure, a rougher cut. A blade that looks brown between the teeth is usually dirty, not finished.

Clean carbide with a dedicated pitch and resin remover or a simple degreaser. Avoid oven cleaner and other caustics — they attack the brazing that holds carbide tips to the plate.

When to Resharpen

Carbide-tipped blades and bits are resharpenable, generally several times, until there isn't enough carbide left to grind. Send them out when:

• The cut quality drops after cleaning has been ruled out
• Feed pressure climbs noticeably
• You can see light reflecting off a rounded cutting edge

Solid carbide spirals can often be reground as well, though small diameters reach their limit sooner.

Replace rather than resharpen when a tip is chipped past the grind depth, the plate is warped, or the brazing has failed.

Storage

Carbide is hard and brittle — it chips against other steel. Store bits and blades so their edges don't touch anything:

• Keep router bits in their cases or a drilled block, not loose in a drawer
• Hang or sleeve saw blades individually
• Keep a light film of protectant on plates and shanks in a humid shop

Setup Problems That Look Like Tool Problems

• Burning — usually too slow a feed rate, too dull an edge, or a misaligned fence.
• Chatter — deflection. Check for a shank in too little collet, an unsupported workpiece, or a worn bearing.
• Tearout on the top face — often the wrong flute direction. A down-cut or compression bit fixes what an up-cut tears.
• Inconsistent depth on a flush trim — check the bearing for play before blaming the cutter.

Questions

If you're not sure whether something is worth resharpening or should be replaced, tell us what it is and what it's doing. We'd rather tell you to clean a blade than sell you a new one you don't need.