How to Sharpen Wood Planer Blades for Durability and Cost-saving

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With use, cutting edges of blades lose their sharpness, becoming blunt and unusable.

In such a case, you’ve two options: either you replace the blades with new ones or re-sharpen them.

The first option is expensive, as you’ve to buy new blades from the manufacturer.

But if you want to cut costs of replacing blades from time to time, then the latter option is cost-effective, as you make use of what’s already present.

However, re-sharpening isn’t straightforward. While doable, it’s a time- and effort-consuming process.

Most thicknessing devices come with two types of blades:

  • Single-edged knife
  • Double-edged knife

Re-sharpening is much easier with a double- than a single-edged knife, since you simply need to switch the blunter side with a sharper side.

And that counts toward more durability, because it can take lots of time and cuts to have both cutting edges go blunt, saving you from the hassles of frequent re-sharpening and the costs of replacements.

Read this guide to learn more about how to sharpen wood planer blades.

Re-sharpening for More Cost-Saving and Greater Durability

Blunt blades are more imprecise and shorter than their sharper counterparts. They produce leave ugly marks or raised ridges on the surfaces of work-pieces.

Cutting edges of blades can develop nicks as a result of chipping. When chipped, wood pieces come out of the device with raised ridges.

Re-sharpening thickness planner blades

Sometimes, the resin can cover the knife edges, giving the false impression that the knives are blunt.

Ensure you do regular clean-up of knives to remove resin after you’ve removed thicknesses of board stocks that have piled to hundreds of feet.

You’ll avoid unnecessary re-sharpening and help extend knife life.

In addition, don’t let bluntness get worse. When you notice blades begin to lose their edge, act immediately. You won’t have to spend lots to grind away more of the edge.

Some knives have more durable edges than others, as they are made of resistant materials.

Carbide and high-speed steel (HSS) make-up tend to outlast OEM, which loses its edge much quicker. The quality of steel making up OEM is inferior, thin and poorly-tempered.

And so, OEM materials can’t withstand high amounts of heat, which result from friction between the surfaces of the work-piece and the knife edges.

Therefore, you’re more likely to replace them more often if you slice through thicknesses of more abrasive woods like eucalyptus and teak.

Some manufacturers have designed the knives with an intention to prevent re-sharpening and encourage disposal and replacement.

More so that’s the case with double-edged knives, as they can take a long time of use before the edges lose their sharpness.

However, you’re free to re-sharpen disposable knives if you feel that you can’t afford regular disposal and replacement.

Some benchtop thickness planers have knives that come with index pins, which screws hold them on the cutter-head’s exterior.

When the length of a blade decreases, it becomes difficult to grip the board stock effectively for a precise result.

An effective grip is salient, given that the cutting edge of a knife on the cutter-head must come into contact with the wood piece.

Imprecise works require more work, as you need to make more passes for more precision. More work means more time.

Some benchtop thickness planers have replaceable and removable knives while others have fixed. For the latter, you require to buy a jig from your manufacturer or create your own.

For someone who wants to save up on costs, creating a jig on your own is a popular option, but the process is very labor-intensive and time-consuming.

Therefore, you can either remove the knives or re-sharpen them using a jig while fixed in position.

In addition, you can attach the knife to a jig and re-sharpen its edges on a grit stone. Let’s take a look at each option.

How to Remove Knives and Re-sharpening Them

Small screws or bolts hold in place knives on the curved surface of a solid cylindrical roller known as a cutter-head, which spins under the influence of a motor.

  • Use a wrench to untighten the screws holding the knives in place.
  • Turn the screws clockwise, turning them into the wedge to release the pressure of the head of the screw exerts against cutter-head’s slot.
  • Ensure you keep the screws in a safe so you don’t lose them. (You can use rare earth magnets to hold the bolts together in one place after you remove them)
  • Remove knife once you loosen all the screws.
  • Pull out the wedge.
  • To avoid losing the springs pushing up the knife, removing them to avoid losing them.
  • Clean the exposed area, freeing it from wood chips, dust, resin, debris or rust. You can use a blower of compressed air to clean the slot. You can scrape off the dirt that has accumulated on the wedges.

How to use a jig to Re-sharpen Planer Knives

How to use a jig to Re-sharpen Planer Knives

You can either buy a jig or make your own.

Once you remove the knife, you can attach it to a jig and sharpen its edges on a grit stone.

Alternatively, you can create your jig, attach a grit stone on it and slide it across the edge of the knife to reduce bluntness.

Instead of a jig, you can use a grinding machine to sharpen the blade. These machines usually come with a rail where you can insert the knife.

There’s usually an extra rail to clamp the knife. All you need to do is to bring the knife into contact with a grit stone.

As you grind, be sure to make light and slow side-to-side passes to prevent the blade from becoming warm in an area close to the front edge of the rail.

You don’t want an expansion due to heat to cause the knife to bow outward toward the cutter.

Returning the Knives

  • Put back the springs before wedges.
  • Create enough working space by giving every screw in the wedges an extra torque in a clockwise direction.
  • Slip the knives back into position.
  • Tighten the screws until you feel resistance.
  • To avoid over-tightening, loosen the screws so you’re able to slide the knife up and down.
  • Use a wood block to push down the knife to check whether the springs push up the knife back to the original position.
  • Check whether the height of knives is correct by pushing down the knives using a setting gauge. You can do that by tightening the center screw of the wedge before you tighten each screw that the setting gauge doesn’t obstruct.
  • Extract the setting gauge and moderately tighten the rest of the screws.
  • Don’t forget to switch off and unplug your benchtop thicknesser when doing this job.
  • Reconnect the dust collector with the port.


Learning how to sharpen wood planer blades can help you save up on costs of regularly disposing and replacing knives.

While the manufacturer of a planer designs the knives with an intention to dispose and replace once they lose their edge, you can always re-sharpen them.

Re-sharpening can be tedious and time-consuming, especially if you decide to make your own jig. Fortunately, some dealers and manufacturers build jigs, which you can buy.

And it’s not a must you remove the knives to re-sharpen them. You can attach a grit stone on a homemade jig and slide across the edges of the knives to sharpen them.

Alternatively, you can remove the knives, attach them on a jig and sharpen them on a grit stone.

There are also grinding machines, which can save you from the need of having to use a jig for re-sharpening.


This is Abraham. Professional power tools mechanic with years of experience. Writing is my hobby. So I decide to share my experience with people by writing about all types of power tools review and buyers guide that I'm using.

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