Diamond / CBN Grinding Wheel Calculator

Surface speed (m/s) = π × Wheel Diameter (m) × RPM ÷ 60. For example, a 150mm diameter wheel at 3000 RPM has a surface speed of π × 0.150 × 3000 ÷ 60 = 23.6 m/s.

MRR = Depth of Cut × Wheel Width × Table Speed. It measures how much material is removed per minute, typically in cm³/min. Higher MRR means faster grinding but may affect surface finish.

Maximum safe speed depends on bond type: resin bond ≤35 m/s, vitrified bond ≤60 m/s, metal bond ≤30 m/s, electroplated ≤40 m/s. Exceeding these limits risks wheel breakage. These are typical industry values — always verify against the maximum operating speed printed on the specific grinding wheel.

Flood coolant is recommended for most diamond and CBN grinding operations. It extends wheel life, improves surface finish, and prevents thermal damage. Dry grinding is generally not recommended for resin bond wheels.

To convert wheel surface speed to spindle speed: RPM = (SFPM × 12) ÷ (π × wheel diameter in inches). For example, 4638 SFPM on a 6-inch wheel gives RPM = (4638 × 12) ÷ (π × 6) ≈ 2950.

G-ratio is the ratio of workpiece material removed to grinding wheel volume worn away. A G-ratio of 30 means 30 cm³ of material removed per 1 cm³ of wheel wear. Higher G-ratio means longer wheel life and lower wheel cost per part. Typical values range from under 10 for conventional abrasives to well over 100 for metal-bond superabrasive wheels.