Screw Jack – Allowable Lifting Speed, Torque & Power – Complete Technical Guide
Screw Jack – Allowable Lifting Speed, Torque & Power
The allowable lifting speed, torque, and power of a screw jack are interdependent parameters that determine the correct model selection. The values below apply to ambient temperature 20°C and duty cycle 20%/h or 30%/10min
Key Limits
| Parameter | Limit |
| Maximum Input Speed | 1,500 r/min |
| Maximum Lifting Speed | 2.7 m/min |
| Maximum Input Power | Up to 33.2 kW |
| Output Torque Range | 1.8 – 2,430 N·m |
Power & Torque Calculation
Drive Power:
P = (Fa × v) / (60 × η)
Where P = power (kW), Fa = lifting force (kN), v = lifting speed (m/min), η = total efficiency
Drive Torque:
Mt = 9550 × P / n
Where Mt = torque (N·m), P = power (kW), n = input speed (r/min)
SWL Series Reference Data (at 1,500 r/min)
| Model | Max Lifting Force (kN) | Screw Thread | Power (kW) | Torque (N·m) |
| SWL2.5 | 25 | Tr30×6 | 0.375 | 18 |
| SWL5 | 50 | Tr40×7 | 0.91 | 18 |
| SWL10 | 100 | Tr58×12 | 1.1 | 108 |
| SWL20 | 200 | Tr65×12 | 4.8 | 228 |
| SWL35 | 350 | Tr100×18 | 15 | 464 |
Values vary with load – higher loads reduce allowable speed and power
Selection Rules
Load first – determine required lifting force (kN)
Speed second – verify lifting speed against allowable values
Power third – calculate required input power; if > allowable, select larger model or reduce speed
Important: Values within the bold line range cause overheating – avoid selection
Download Full Parameter Tables
[Download SWL Series Complete Power & Torque Tables (PDF)]
Need help with selection? Send us your load, speed, and stroke – our engineering team responds within 24 hours.
