A bench grinder sits bolted to your workbench and spins abrasive wheels at high speed. It sharpens chisels, drill bits, and garden tools. It removes rust, cleans metal, and shapes parts. It is one of the least expensive and most underappreciated tools in the home workshop. A basic 6-inch grinder costs $50 to $80 and lasts for decades.

Bench Grinder Guide: Sharpening, Shaping, and Cleaning

Choosing a Bench Grinder

For home use, a 6-inch grinder with a 1/3 to 1/2 HP motor is sufficient. The 8-inch models are larger and more powerful but unnecessary for most homeowners.

Look for these features:

Adjustable tool rests: Solid rests that lock at various angles for controlled grinding
Eye shields: Clear plastic shields that flip down to protect your face
Accessible wheel guards: For easy wheel changes
Smooth operation: The grinder should run with minimal vibration

Grinding Wheels

Most bench grinders ship with two wheels:

Coarse wheel (36-grit): On the left side, used for rough shaping, heavy material removal, and aggressive sharpening. This wheel removes metal fast.

Fine wheel (60-grit): On the right side, used for finish sharpening, light shaping, and honing edges.

Replace the stock wheels over time with:

White aluminum oxide wheels: Run cooler and are less likely to burn tool steel. Ideal for sharpening chisels and plane blades.
Wire wheel: A wire brush wheel removes rust, paint, and scale from metal parts. Essential for outdoor project hardware cleanup.
Buffing wheel: A cloth wheel used with polishing compound for bringing an edge to a mirror finish.

Sharpening Chisels and Plane Blades

Chisels are the most commonly sharpened tool on a bench grinder. Set the tool rest to the desired bevel angle (25 degrees for most bench chisels) and:

Turn on the grinder and let it reach full speed
Position the chisel flat on the tool rest with the bevel facing the wheel
Move the chisel slowly side to side across the wheel face
Apply light pressure — let the wheel do the work
Dip the tool in water frequently to prevent overheating, which turns the steel blue and softens the edge

After grinding, hone the edge on a sharpening stone or leather strop for a razor-sharp result. Sharp chisels make woodworking projects safer and more enjoyable.

Sharpening Drill Bits

Dull drill bits generate heat, wander off center, and produce rough holes. A bench grinder can restore them:

Hold the drill bit at approximately 59 degrees to the wheel face (the standard point angle)
Touch the cutting edge lightly to the fine wheel
Rotate the bit slightly to grind the relief angle behind the cutting edge
Repeat on the other cutting edge, keeping both sides symmetrical

This takes practice. A drill bit sharpening jig ($15 to $30) clamps onto the tool rest and holds the bit at the correct angle automatically.

Safety Rules

Bench grinders demand respect. The wheel spins at 3,450 RPM and can grab loose items, throw sparks, and break apart if misused.

Wear safety glasses or a face shield at all times
Keep the tool rest within 1/8 inch of the wheel. A gap allows material to jam between the rest and the wheel.
Stand to the side when first turning on the grinder. If a wheel has a crack, it is most likely to break in the first few seconds.
Never grind on the side of the wheel unless using a wheel rated for side grinding
Do not wear gloves, loose clothing, or ties near the spinning wheel
Keep a container of water nearby for cooling metal during sharpening

Ring Test Your Wheels

Before installing a new grinding wheel, hold it by the center hole and tap it gently with a screwdriver handle. A good wheel produces a clear ring. A cracked wheel sounds dull or dead. Never install a wheel that fails the ring test.

Maintenance

Dress the wheel surface periodically with a diamond or star wheel dresser to expose fresh abrasive and keep the face flat
Check the tool rests before each use and adjust the gap
Keep the grinder bolted securely to a sturdy workbench
Clean the eye shields so you can see your work clearly

A bench grinder is a workshop essential that keeps your other tools sharp and your projects running smoothly.