How To Sharpen A Saw Blade Homemade Machines & Jigs

Dull saw blades? Sick of sending them out? In this article I use a diamond wheel on my table saw to sharpen carbide saw blades to like-new condition.

Actually, not quite “like-new”, but definitely sharp enough for silky smooth cuts. The fact is, even if you send it out to a pro shop to have it sharpened, it still won’t be as good as it was out of the package. And it’s important to understand that and accept it before doing this. There’s always a trade-off. In this instance, it’s convenience and low cost for less than perfect performance.
With all that said, I’ve had blades sharpened many times and effectively extended their life over several years. Imagine buying a new blade as soon as the old one became dull, and how much that would cost.

This is actually an update to an older article on sharpening blades. In that one, I did it free-hand and in this one, I make a simple jig. That starts with a plywood base with a guide cleat on the bottom that fits in the miter slot on the saw:

I also cut a groove sideways across the top for tooth angle adjustment where it meets the grinding wheel.

Since I have blades with two different arbor hole sizes, I made two bars that fit snugly in the slot:

And made plywood disk the right size to fit into the arbor holes. A 5/8″ and 1″. The belt / disk sander is perfect for fine tuning the size:

The bars have recessed slots in both ends for adjustment:

To index the teeth, I made a simple flip down (and up) stop from a piece of 1/8″ flat steel. It’s screwed to the end of a hardwood block with oversized holes, and these holes allow for some adjustment:

The 6″ grinding wheel has a diamond impregnated ring on one side of the rim. Diamond (or CBN – cubic boron nitride) is the only way to grind carbide. Regular abrasives are ineffective and will overheat the tooth causing it to fracture. Also, I recommend not using things like diamond cutting wheels made for tile. The grit is to coarse to create a good cutting edge.

The wheel isn’t cheap, but I figure it pays for itself after three sharpenings.

Worth pointing out that this makes some very nasty dust and it’s a good idea to wear breathing protection:

I sharpened five blades in this session – good for another year or so, and show some of that in this video: