High-speed steel (HSS) knives are easier to resharpen and work well for most hardwoods and softwoods. Carbide-tipped knives hold an edge significantly longer, making them the better choice for abrasive materials like MDF, plywood, or reclaimed lumber with mineral deposits.

Replacement knives must match your machine's cutterhead in length, width, and thickness. Check your planer's manual for the knife dimensions, then compare to the product specifications listed for each knife set — for example, Infinity offers dedicated replacement knives for the DeWalt DW735 and other popular models.

Even a small difference in height between knives causes uneven cutting, chatter, and snipe. A knife-setting jig registers each knife to the same precise height relative to the cutterhead, ensuring a smooth, level cut from the first pass. It also speeds up knife changes considerably.

Carbide-tipped planer knives can be honed with a diamond stone to extend their service life between replacements. The diamond knife hone is designed specifically for both HSS and carbide jointer and planer knives and restores the cutting edge without removing excess material.

A digital readout mounts to your portable planer and displays the actual cutting depth in real time, so you can plane stock to an exact thickness without repeated measuring and test cuts. It is particularly valuable when milling multiple boards to a consistent dimension for glue-ups or panels.

Hidden staples, nails, or screws in reclaimed or pallet lumber can chip or shatter planer and jointer knives in an instant. Running stock through the Little Wizard II metal detector before milling identifies any embedded metal so you can remove it before it contacts the cutterhead.

Replacement frequency depends on the hardness and abrasiveness of the wood you process and the total volume of material milled. Signs that knives need attention include fuzzy grain, visible mill marks, increased resistance, or burning on the wood surface. Regular light honing extends knife life significantly.

A planer flattens stock to a consistent thickness but references off one face — if that face is cupped or bowed, the planer will replicate the warp. A jointer creates a single flat reference face first, which the planer then mirrors on the opposite side. Both machines are used together for truly flat, parallel boards.

Always disconnect the machine from power before removing or installing knives. Handle knives with a folded cloth or leather gloves — never bare hands. Lower the cutterhead guard back into place before reconnecting power, and confirm all knife-locking bolts are torqued to spec. Visit the Infinity Tools learning center for technique guides.

Yes — most jointer and planer knives and accessories are stocked and ship promptly. See the shipping policy page for current lead times and carrier options.