Choosing the Right Drive Wheel Size for Your 2x72 Belt Grinder

When buying your first belt grinder, picking the right drive wheel is key to dialing in the ideal belt speed for your grinding needs. Most knifemakers find that a belt speed between 40–60 MPH gives the best results for general-purpose grinding and finishing.

Your drive wheel size depends on your motor’s RPM. Use our Belt Speed Calculator to match the right drive wheel with your motor. Here are some common speed outcomes:

Belt Speeds by Drive Wheel Size

With a 4" Drive Wheel

• 1200 RPM → 14 MPH (Perfect for sharpening and small wheels)

• 1800 RPM → 21 MPH

• 3450 RPM → 41 MPH

• 3600 RPM → 43 MPH

With a 5" Drive Wheel

• 1200 RPM → 18 MPH

• 1800 RPM → 26 MPH

• 3450 RPM → 51 MPH (Ideal for general grinding)

• 3600 RPM → 53 MPH

With a 6" Drive Wheel

• 1200 RPM → 21 MPH

• 1800 RPM → 32 MPH

• 3450 RPM → 61 MPH

• 3600 RPM → 65 MPH

With a 7" Drive Wheel

• 1200 RPM → 25 MPH

• 1800 RPM → 37 MPH

• 3450 RPM → 72 MPH

• 3600 RPM → 75 MPH

Tips:

• For fine control and versatility, especially with small wheels or knife sharpening, stick to smaller drive wheels or reduce your motor speed with a VFD.

• If you're looking for a workhorse setup for stock removal and general grinding, a 5" or 6" drive wheel paired with a 3450–3600 RPM motor is your best bet.

Still unsure? Reach out—we’re happy to help you spec your setup!