Set First, Then Sharpen? Or the Other Way Round?

Sawmill operators discuss the order of steps for sharpening blades. April 20, 2011

Question
My partner and I have a wager going on the answer to this question; when sharpening and setting the blade, do you sharpen first or set first, and why?

Forum Responses
(Sawing and Drying Forum)
From contributor J:
To me it is simple, set first, sharpen second. Otherwise you have to sharpen anyways after setting. No brainer!



From the original questioner:
I have tried it both ways and find that sharpening first works best. When you sharpen first the very tip of the tooth is square with the blade body from side to side. As you set the tooth the tip is pushed to the side and is out of square with the body. The blade acts like a dull blade. When you set first the tip stays square with the body giving a sharper point on the outer side of the tooth tip.


From contributor T:
I don't set on every sharpening unless the blade was leaving the tell-tale signs of it. Agreed a point can get knocked too far in and you wouldn't know it from reading the lumber but I have had good results. I set every third sharp unless it needs setting sooner. Always set first like the others.

I have been sharpening lately using a pneumatic cutting tool with a grinding blade on it. I have WM a grinder but both motors are out so one day in a bind I decided to just manually sharpen a blade to get through the rest of the logs. I wasn't planning on doing it more than once, but I've been doing them manually ever since. I can blast through one now in about 12 minutes, and I know I'll be accused of delusion but the blades seem to stay sharper longer than when I would send them off to WM Re-sharp. Not only that, I never get the second or third rejects out of a dozen blades I was guaranteed to get with them either.




From contributor A:
Set is a very important thing. The set is so that the teeth cut a wider path than the body of the blade. So much sawdust is to spill out of the gutlet of the blade and remain behind in the cut. If you set and then sharpen your set width will be less. This will cause more heat buildup in the blade. If you sharpen then set your grind on the face of the set teeth will be out of plane with the bottom of the cut. That is not a bad thing.

When I look at a new WM blade it looks like they grind the new teeth and then bend them to set when the blade is cut and welded. A new blade leaves a different cut pattern on the lumber. A blade returned from Re-Sharp will cut a smoother finish on the lumber. So I guess I am in the camp of sharpen then set. But what do I know? I only run Re-sharp blades and we saw close to a million bdft a year.



From the original questioner:
This has been an interesting topic. It seems the majority say to set first, the other bends toward sharpening first; both with valid justification. My thoughts on it bend toward setting first when the blade is newer, and setting first after two or three sharpenings. I've done the math on the amount of metal removed when sharpening (on a generic level) and the resulting set change, and it seems that most setting machines cannot be precise enough to make an early-blade difference when sharpening. I agree it seems a new blade is sharpened then set, making the set teeth lower than the straight teeth until the first sharpening; a good reason a new blade would cut different from a sharpened blade. Guess I'll monkey around with a couple and see how things go. Thank you all for your input, any more will be appreciated.


From Gene Wengert, forum technical advisor:
A larger commercial operation will set first and then sharpen. Similarly, when swaging with a circular or band blade, swage first and then sharpen.

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