Free Engineering Tool #075
Spline Connection Calculator — ISO 4156
Involute spline geometry per ISO 4156 (metric module, side fit). Enter module, number of teeth, pressure angle, engagement length, and torque for a simplified bearing-stress and torque-capacity estimate — a common design practice, not part of ISO 4156.
Results
Pitch Diameter
Simplified Spline Bearing-Stress Estimate
where h = effective tooth height (approx 0.9m), z = teeth, L = engagement length, K = load distribution factor, Dp = pitch diameter.
Load distribution: K=0.75 fixed, K=0.5 sliding under load. This calculator uses K=0.75.
Note: ISO 4156 defines involute spline geometry, tolerances, fits and inspection — it does not specify a load-capacity method. The bearing-stress, torque-capacity and safety-factor results above are a simplified engineering estimate (uniform load sharing, effective tooth height h ≈ 0.9m, empirical factor K) commonly used in design practice; they do not constitute ISO 4156 compliance. Verify critical designs with detailed analysis.
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.
