Router Bit Sharpening

Carbide Woodturning Tools For The B...
Carbide Woodturning Tools For The Beginner

Router bit sharpening is something that you should learn how to do yourself. In the long run it’ll save you a lot of money and time before you have to send it off to a professional. The good thing when it comes to sharpening router bits is it doesn’t take long to do it. It also doesn’t take any special skills. Plus it’s just a good maintenance practice.

Can Router Bits be Sharpened?

Yes, they can and it’s really easy to do. I would encourage anybody who uses router bits to sharpen them. It doesn’t require a special technique or tools to do this. All that’s needed is a diamond paddle or two and a wood clamp.

The diamond paddles you want are 600 grit and 300 grit. You may be able to find one paddle that has both grits that you need. The 600 grit will probably be the one that you use the most. It’s mainly used for touching up to bring back the sharp edges.

This only works if the bit still has somewhat of a sharp edge and you just need to touch it up a bit. If the bit is really dull or has really noticeable blunt spots, then that’s when you want to start sharpening with the 300 grit. Then finish it off with the 600 grit. 

Whatever you do, don’t go with finer grit such as a 1000 grit diamond paddle. Too much of a sharp edge will cause it to break off when you go to use it. This will leave you with a duller bit than what you started with. Then you’ll have a lot more work to get it back to sharp. 

Eventually you’ll have to have them sharpened by a professional that has the right equipment to get them back where they need to be. But until then you might as well sharpen them yourself and save money in the process.

Is it Worth Sharpening Router Bits?

Taking them to somebody to have them sharpened could cost you half the price of what you paid for the bit when you purchased it. Also keep in mind, the bigger the bit and more cutting surfaces the more it’ll cost you to get them sharpened.

Eventually all bits you use will need to be sharpened by a professional but we can cut down on the trips. So yes it is worth the time and money to sharpen your own. 

How to Sharpen Router Bits

Before you can sharpen router bits it’s important that you clean all the resin and build up off the bit before you start.

The steps to follow when sharpening a router bit:

  1. Clamp the diamond paddle to a flat surface to give better control when making the passes over the paddle. 
  2. Remove the bearing if there is one.
  3. Never sharpen the profile edge of the bit.
  4. Only sharpen the cutting edges or the flat sides of the bit.
  5. Moisten the diamond paddle with a little water for lubrication.
  6. As you lightly move the bit across the paddle, count the strokes so that the bit stays balanced. It should only take five to ten strokes per cutting edge to get it sharp.
How to Sharpen Router Bits

How Often Should You Sharpen A Router Bit?

How much you use a bit will determine how often you should sharpen it. If you use it constantly you’ll have to sharpen it more often.

There’s no set time for when you should sharpen your bits. It depends on multiple things. Plywood and other sheet goods will dull a bit pretty fast because of the resin build up on the bit.

Plus the resin in sheet goods is pretty abrasive so you can imagine the toll it takes on a sharp bit.

Solid types of wood can dull bits fairly fast. Though carbide router bits are better at holding an edge than high speed steel bits, they will still get dull if you’re using them a lot.

The speed on your router if set to fast definitely will dull your bit faster than normal. When the bits turn too fast it creates friction. Too much friction on any bit will dull it. 

If you’re feeding the material too fast into the router or moving the router too fast through the wood that’ll make it dull faster too.

How do I Know if my Router Bit is Dull?

How do you tell if you have a dull router bit? There’s a few things that can indicate dullness.

When you hold the bit up to a light, look and see if you can find any shiny spots on the bit or blunt spots. This definitely means that your bite is dull.

Another thing that tells us that a bit isn’t sharp anymore is the cut on the wood. If the cut is rougher than it should be then it’s time to resharpen it.

Look for tear out especially on end grain of the routed part of the wood, if there’s more than what you normally see that’s a good indication of a dulled bit.

If you find that you have to put more effort in getting the router to go through the wood then that’s another indication that your bit may be dulling.

Burnt spots on the wood will sometimes happen with a dull bit. Especially if you know that the speed on the router is correct and that the feed rate is right.

Put the cutting edge on your finger nail and lightly rotate the bit. Without much effort it should shave a little of the nail if it’s still sharp.

If you’ve already sharpened the bit in question and you’re not sure of the sharpness, you can try running the bit through some scrap softwood to see how it cuts. If it produces sawdust more than shavings then it’s probably time to be sharpened professionally.

How Many Times Can You Sharpen A Router Bit?

A router bit can be sharpened around only five or six times. Anything beyond that you’ll have to take it to somebody who can professionally get them back to sharp. 

How to Keep Router Bits sharp?

Invest the money into decent quality bits. This alone will make router bits last longer. I would suggest carbide because they stand up to heat better than high speed steel.

Once you’re done using the bit, inspect it before putting it away. Router bit maintenance is pretty important if you want them to stay sharper and last longer.

A good quality carbide router bit will last a while before you need to hone it. The important thing is to keep up on it if needed. 

References:

Learn how to use diamond paddles for sharpening router bits.