Free Engineering Tool #074
Keyway Calculator — DIN 6885
Key sizes per DIN 6885 (formerly ISO/R 773, withdrawn). Enter shaft diameter and torque to find the standard key size and run simplified shear and bearing stress checks.
Results
Tangential Force
Shear Stress in Key
Bearing Stress
Standard Key Sizes (DIN 6885)
Key cross-sections below follow DIN 6885. The corresponding ISO recommendation, ISO/R 773, has been withdrawn and is mentioned here for historical reference only; it listed the same sizes but is no longer a current ISO document.
| Shaft d (mm) | Key w×h (mm) |
|---|---|
| 6–8 | 2×2 |
| 8–10 | 3×3 |
| 10–12 | 4×4 |
| 12–17 | 5×5 |
| 17–22 | 6×6 |
| 22–30 | 8×7 |
| 30–38 | 10×8 |
| 38–44 | 12×8 |
| 44–50 | 14×9 |
| 50–58 | 16×10 |
| 58–65 | 18×11 |
| 65–75 | 20×12 |
| 75–85 | 22×14 |
| 85–95 | 25×14 |
Key length = 1–1.5× shaft diameter. Check stress concentrations at keyway corners (Kt=1.5–2.5). The shear and bearing formulas above are simplified engineering checks assuming uniform stress distribution — they are common design practice, not requirements of any current ISO standard.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
