Wise Buys: Bench Grinders
Woodworkers use this tool mainly for sharpening, but also for grinding down hardware, and, with wire wheels or cloth buffing wheels, cleaning and polishing. A variable-speed machine better suits this wide range of jobs than a single-speed, 3,450-rpm model. Slow the tool for sharpening; use higher speeds for cleaning, buffing, and polishing.
We prefer an 8" grinder because the 1"-wide wheels provide a broad sharpening surface, and the fast rim speed grinds and polishes quickly. 6" models cost less, but cut slower (better for sharpening), and provide only 3⁄4 "-wide wheels.
We tested 11 slow- and variable-speed models and found these three offer good value for the daily grind.
Craftsman 21162 (8"); 21154 (6")
Wheels: 60-grit silicon carbide, wire brush
RPM: 1,800-3,315 (8"); 1,870-3,180 (6")
If you change wheels frequently, you'll appreciate this grinder. Removing just one threaded knob frees the wheel cover. An included wrench holds the motor shaft while you loosen the arbor nut. The same wrench helps you loosen the tool rests for sliding them forward and back.
The grinding wheel works for touching up tool edges, and I used the wire wheel to clean rust from an old hand plane. The included accessories offer a mixed bag of performance: The star-wheel dressing tool works fine for truing 60-grit and coarser wheels; a drill-bit sharpening plate mounts on either tool rest (but I had little luck reviving bits with it); a handy quench cup clips to the base and holds water for cooling tools while sharpening.
The 6" and 8" versions of this grinder have near-identical features, so let your needs and wallet dictate your choice.
Get it if: You need rough grinding as well as wire-wheel cleaning.
Forget it if: You expect razor-sharp tools from the 60-grit wheel.
—Tested by Craig Ruegsegger, Projects Editor
To learn more:
Porter-Cable PCB575BG (8") $119; PCB525BG (6")
Wheels: 36- and 80-grit silicon carbide
RPM: 2,075–3,425 (8"); 2,065–3,435 (6")
The wheels of these similarly featured grinders cover a wide range of tasks, from rough grinding to touching up woodworking tools. Both grinders run nearly vibration-free, with smooth rpm changes across the variable-speed range.
Threaded knobs make positioning the tool rests and safety shields easy. The poker-chip-like interlocking ridges in the tool rest and mount provide solid, repeatable positioning, but prevent fine-tuning between those gradations. A T-shaped, diamond-embedded dressing tool stores on the back of the base and a quench cup sits up front.
Two gripes: I didn't care for the drill-bit-sharpening groove cast into the left tool rest, as narrow chisels tended to dip into it. And the task light only comes on when the motor is running, so it can't be used when setting up the grinder.
Get it if: Sharpening chores range from lawnmower blades to chisels.
Forget it if: You want a grinder mostly to touch up woodworking tools.
—Tested by Lucas Peters, How-to Editor
To learn more:
Woodcraft 150780 (8")
Wheels: 60- and 120-grit aluminum oxide
This affordable, single-speed grinder doesn't offer a task light or a dressing tool, but in exchange you get high-quality, aluminum-oxide wheels meant for sharpening tools. And for what those wheels would cost as an upgrade, you could easily add a light and dressing tool, and still be money ahead. The grinder's slow speed means minimal vibration: It stayed put on my bench, even without clamping it in place.
However, I had to double-faced-tape wedges to the fixed-angle tool rests to hold my plane irons at the proper angle. Adusting the tool rests forward and back requires a wrench that you provide. Although you could mount a wire wheel or buffing pad, doing so requires removing five screws from the wheel cover. And the slow speed means jobs with these accessories will take longer.
Get it if: You touch up woodworking tool edges frequently.
Forget it if: You're not willing to work a bit to set it up.
—Tested by Karl Ehlers, Art Director
To learn more: