Sharpening Insert Tooling

Some insert-type cutterheads can be sharpened once or twice, but it's a tricky process that can create complications. July 30, 2007

Question
I use custom insert cutter heads for some of my longer run profiles. I have asked my local sharpening service if he can sharpen them and he tells me that they are one-use tools. Does anyone know if inserts can be sharpened, and is it worth it?

Forum Responses
(Solid Wood Machining Forum)
From contributor T:
Your sharpener is half right. In some instances, inserts can be sharpened with little problem. In the case of inserts that are made to cut interlocking profiles, I do not recommend sharpening them. Stile and rail and tongue and groove inserts are a bad choice to have sharpened, as the fit may prove difficult after sharpening. If you do sharpen these types of inserts, try not to have them sharpened more than once.

Now the good news. For all other inserts that do not cut interlocking profiles, you can sharpen them multiple times. Just keep in mind that they should not be sharpened down more than half their thickness, as breakage could occur during cutting. If an insert breaks during cutting, it can damage the insert head or hurt nearby people.



From Dave Rankin, forum technical advisor:
It is very important to speak with the tool designer prior to having inserts sharpened. For example, Terminus knives can be sharpened once. Profile inserts can be sharpened in a couple of different ways depending upon the design. We have sharpened many profile inserts in the diameter if the tool body is designed to allow for this. When you face grind the carbide, you may change the profile and reduce the safety factor of the tool.


From contributor J:
We have a well equipped sharpening shop here in Colorado that has been doing our Garniga shaper inserts and moulding inserts for our S4S machine. They have a German machine that holds the inserts magnetically. At first they were removing too much thickness, but now have it perfected and only remove a little from the profiled face without touching the face that tightens against the gibs. I have found we can get 1 or 2 sharpenings on the flooring and cope and stick inserts before it changes the fit. Other profiled inserts like the top part of our raised panel head should be able to be sharpened a few times. I have not tried the 1.5mm thick euro reversible straight cutters like in a rebate head. They are inexpensive to start with and would probably need the whole face removed. Sharpening cost is about $8 per insert. The company is Bakke Saw Service in Fairplay, CO.