Three calculators for grinding operations: wheel peripheral speed, material removal rate with specific energy, and surface finish Ra estimation. All in one place, no account needed.
Vs = (π × D × N) / 60000Vs = (π × D × N) / 12q = Vs / Vw| Operation | Wheel Speed (m/s) | Work Speed (m/min) | Notes |
|---|---|---|---|
| Surface Grinding (reciprocating) | 25–33 | 6–30 | Flat surfaces, good finish |
| Surface Grinding (rotary table) | 25–33 | 10–40 | Higher productivity |
| Cylindrical (external) | 28–35 | 15–30 | Most common operation |
| Cylindrical (internal) | 18–28 | 20–60 | Smaller wheel, lower speed |
| Centreless Grinding | 28–35 | 20–80 | High production, no chuck |
| Tool & Cutter | 18–25 | 1–10 | Complex geometry, slow work |
| High Speed Grinding (CBN) | 45–120 | 60–200 | Special spindle required |
Q'w = ae × VwQw = ae × Vw × bPc = u × Qw / 1000| Material | Specific Energy u (J/mm³) | Wheel Grade | Notes |
|---|
Ra ≈ K × (Vw/Vs) × ae^0.5 / G^0.75d_grain ≈ 15200 / G (μm)| Grit Grade | Grit Number | Ra Typical (μm) | Application |
|---|---|---|---|
| Very Coarse | 10–24 | 8–25 | Heavy stock removal, rough shaping |
| Coarse | 30–46 | 3.2–8 | Rough cylindrical, cast iron dressing |
| Medium | 54–80 | 1.6–3.2 | General surface grinding, most steels |
| Fine | 90–120 | 0.8–1.6 | Finish grinding, bearing surfaces |
| Very Fine | 150–220 | 0.4–0.8 | Precision grinding, gauges |
| Ultra Fine | 240–600 | 0.1–0.4 | Superfinish, lapping operations |
| Micro / CBN | 800+ | <0.1 | Mirror finish, optical surfaces |
Grinding is one of those operations that every machining student studies but rarely gets good tools for. You open a browser, search "grinding wheel speed calculator", and you get either a 10-year-old Flash widget or a PDF from some university that requires you to interpolate values off a graph.
The wheel speed one is critical because it is a safety thing. Running a wheel above its rated speed can break it apart. That is not a surface finish problem, that is a workshop safety problem. I wanted something that shows the result clearly and flags when you are getting close to the max.
Whether you are at a polytechnic lab, a production shop, or prepping for GATE, you deserve the same tools as anyone with a paid software subscription. No account. Works on your phone. That is the whole point.
If something looks wrong in the numbers, tell me. Surface finish estimation especially is empirical, and the formula has limits. I would rather know and improve it than leave people with a bad result.