Spline Torque Capacity
Estimate torque capacity T of an involute spline from tooth-side contact (n teeth, height h, length l, mean radius rm, allowable shear τ).
Inputs
Formula
Fundamentals
Estimate torque capacity T of an involute spline from tooth-side contact (n teeth, height h, length l, mean radius rm, allowable shear τ).
This tool computes Spline Torque Capacity from the formula: T = n·h·l·rm·τ / 2
History
Design theory of gears, threads and bearings matured with machine tools and standardisation (AGMA, ISO) since the Industrial Revolution.
Engineering applications
Used for transmission design, joint strength checks and component selection.
Glossary
| Teeth n | Input parameter |
| Tooth height h | Input parameter |
| Engaged length l | Input parameter |
| Torque capacity T | Output result |
How to use
- Fill in Teeth n, Tooth height h, Engaged length l, Mean radius rm, Allowable shear τ in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Torque capacity T in the results area.
Formula · Worked Example · Knowledge
Formula
核心计算关系：T = n·h·l·rm·τ / 2
输入变量：
- Teeth n
n - Tooth height h
h— mm - Engaged length l
l— mm - Mean radius rm
rm— mm - Allowable shear τ
tau— MPa
输出结果：
- Torque capacity T
T— N·mm
假设/适用：Gearing/thread formulas assume standard, zero-backlash mounting; include error & load factors K_A.
Worked Example
根据公式 T = n·h·l·rm·τ / 2，取 Teeth n = 10；Tooth height h = 2 mm；Engaged length l = 40 mm；Mean radius rm = 20 mm；Allowable shear τ = 40 MPa。
代入计算得：Torque capacity T = 320,000 N·mm。
Key Points
- Gearing/thread formulas assume standard, zero-backlash mounting; include error & load factors K_A.
- Compare stress with allowable stress and keep a safety factor (≥1.5, ≥2 for critical parts).
- For high speed/load also check lubrication, heat and fatigue life, not just static strength.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| Teeth n | n | 10 | |
| Tooth height h (mm) | h | mm | 2 |
| Engaged length l (mm) | l | mm | 40 |
| Mean radius rm (mm) | rm | mm | 20 |
| Allowable shear τ (MPa) | tau | MPa | 40 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Torque capacity T | T | N·mm |
Applications
- Common engineering use cases