S series gearbox torque and service factor are attached in the official parameter table of S37-S97
1. Torque – What the Numbers Actually Mean-gearbox ambient temperature
S series gearboxes cover a wide torque range. Here‘s the quick reference for the most common sizes
| Model | Max. Permissible Torque (N.m) | Input Power Range (kW) |
|---|---|---|
| S37 | 90 | 0.18 – 0.75 |
| S47 | 170 | 0.18 – 1.5 |
| S57 | 300 | 0.18 – 3.0 |
| S67 | 520 | 0.25 – 5.5 |
| S77 | 1,270 | 0.55 – 7.5 |
| S87 | 2,280 | 0.75 – 15 |
| S97 | 4,000 | 1.5 – 22 |
⚠️ Important: The “max permissible torque” is the mechanical limit of the gearbox. Your actual working torque must be lower than this number after applying the service factor (see below)
2. Service Factor – The “Safety Margin” You Can‘t Ignore
The service factor (fB) is your gearbox’s safety buffer. A higher service factor means longer life and fewer breakdowns.
What determines your service factor?
Daily operating hours – longer runs = higher factor
Starts per hour – more starts = higher factor
Load type – smooth, medium, or heavy shock
| Application Type | Recommended Service Factor |
|---|---|
| Light duty, < 10 hrs/day, few starts | ≥ 1.0 |
| Medium duty, 10-16 hrs/day | ≥ 1.2 – 1.4 |
| Heavy duty, 24/7 operation, frequent starts | ≥ 1.5 – 2.0 |
Most industrial applications work well with a service factor of 1.4 as a safe starting point.
📐 The math: Required torque × Service Factor ≤ Gearbox rated torque
