Regain Your Edge
Cuts that chip, burn, and bog down your tablesaw motor signal a blade that's lost its edge. That doesn't mean your blade's ready for the trash, though. Today's sharpening services can restore most saw blades up to 10 times. Sharpening prices vary by the number of teeth on a blade, but expect to pay $12 to $22 plus shipping and the cost of any needed repairs.
When, what to resharpen
Tip 1: Send blades out for sharpening at the first signs of dulling. If you wait so long that the carbide becomes severely worn, the sharpening service will need to remove more of each tooth to restore an edge, reducing the number of times it can be resharpened.
Tip 2: Warped blades or those with missing teeth may not be worth repairing. Discard any blade that shows signs of cracking.
Tip 3: Remember your dado set when it comes time to sharpen blades. Most services can handle any of the commonly available dado blades, including Freud's Dial-A-Width set once disassembled. To ensure flat-bottomed dadoes, sharpen the chippers along with the blades to remove carbide to a uniform tooth.
Tip 4: When preparing a shipment to a mail-order sharpening service, pack blades carefully to avoid turning small problems into big ones. Spike Burns at Burns Tools in Tiverton, R.I., once received a shipment of loose saw blades with more than a dozen freshly broken carbide teeth at the bottom of the box. Protect blades by taping each one to a separate sheet of cardboard; then tape cardboard on top of each blade to prevent shifting inside the box or metal-to-metal contact.
Pick a sharpening service
The days when anyone with a grinder or file could handle your sharpening needs have gone the way of high-speed steel saw blades. Whether you choose a local or mail-order sharpening service, first ask what equipment they use. Some firms still successfully sharpen blades without automated equipment, but most use computer numerical control (CNC) sharpening machines like the one shown above. These automatically and consistently match their grinding action to the shapes and angles of the blade teeth while a stream of coolant prevents the fragile carbide from overheating.
Blade manufacturers can help you track down such sharpening services. Forrest Manufacturing offers factory resharpening for its blades as well as other makes. Freud doesn't offer factory resharpening, but can refer you to a sharpening service center.
Whichever sharpening firm you choose, ask what comes with the price of the service. This may include removing built-up pitch, inspecting the blade for missing or damaged teeth and repairing them, above checking for runout, and applying a protective coating to the teeth for the return shipment, as shown below. Some will return your blades in reusable protective packages for your next order.
Once you get your blade back from a service you've used for the first time, inspect the quality of the work and look for grinding and repair flaws like those shown below. Then date the blade near the arbor hole using a permanent marker before you put it back in service. A properly sharpened blade should last at least as long as a new one. If not, find a new sharpening service.
Check returned blades for common flaws
Potential saw-blade repair and sharpening mistakes include: 1 teeth brazed on at the incorrect pitch; 2 teeth bevel-ground at the wrong angle or not enough; 3 excessive sidegrinding that damages the blade body; and 4 loosely brazed replacement teeth.
- Acme Tools
- 629 SW 9th St.
- Des Moines, IA 50309
- 800-544-4189, acmetools.com
- Burns Tools, Sharpening Dept.
- 315 Main Road
- Tiverton, RI 02878
- 800-341-2200, burnstools.com
- 3B Saw and Tool
- 6338 W. Roosevelt Road
- Oak Park, IL 60304
- 708-386-2365, 3bsawandtool.com
- Forrest Manufacturing
- 457 River Rd.
- Clifton, NJ 07014
- 800-733-7111, forrestblades.com
800-334-4107, freudtools.com/sharpening for approved services.