Metric Machine Screw Jacks
Screw Jacks
5 to 500 kN load capacity. Metric Machine Screw Jacks offer positive mechanical action, precise positioning, and uniform lifting speeds.
Features and Benefits
Standard configurations include upright or inverted units with translating or rotating lifting screws, and top plate, threaded, or clevis ends.
Mounting dimensions in millimeters. All metric fasteners on machine screw units. Metric bolt centers. Metric screw diameters with trapezoidal threads. Metric bolt centers. Metric screw diameters with trapezoidal threads (machine screw actuators)
Duff-Norton metric machine screw actuators offer positive mechanical action, precise positioning, and uniform lifting speeds.
Since many actuators feature the same gear ratios different capacities can be used in the same application to lift unevenly distributed loads with uniform speeds.
Metric shaft and keyway sizes per ISO recommended standards
Options
Learn More About Duff-Norton Screw Jacks
Industrial screw jacks are used to lift, position (push, pull, tilt, roll, etc.) and support all kinds of loads. Some applications where our screw jacks have been used include plastics machinery, beverage bottling systems, aircraft assembly and paper production.
Duff-Norton’s collection of screw jacks range from mini screw jacks supporting up to 1,000 pounds to acme screw jacks with a capacity up to 350 tons and everything in between. Learn about our machine and ball screw jacks.

Specifications
Performance Table Instructions
When reviewing and Duff-Norton Actuator Performance Specification Table, as part of the process of selecting the best-suited actuator for your application, there are several important worm-gear ratios to consider.
Standard Ratio - is frequently chosen when higher speeds and efficiency ratings are desired.
Optional Ratio - is frequently chosen when the application requires higher lifting capacities, lower speeds, or to ease the use of a handwheel.
Numeric Ratio - is frequently chosen for applications requiring fine adjustments, higher lifting capacities, lower speeds, the easy use of a handwheel, self locking applications, and also offers the benefit of an even number of worm input turns per inch of stroke.
Specifications - Metric Machine Screw Actuators - Capacities 5 to 500 (kN) |
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Capacity (Tons) | 5 | 10 | 25 | 50 | 100 | 150 | 200 | 300 | 500 | |
Lifting Screw | Diameter (mm) | 16 | 20 | 30 | 38 | 52 | 58 | 65 | 95 | 115 |
Lead (mm) | 3 | 5 | 6 | 9 | 12 | 12 | 12 | 16 | 16 | |
Type | Metric Trapezoidal | |||||||||
Worm Gear Ratios | Standard | 5:1 | 5:1 | 6:1 | 6:1 | 8:1 | 8:1 | 8:1 | 10-2/3:1 | 10-2/3:1 |
Optional No. 1 | — | 20:1 | 24:1 | 24:1 | 24:1 | 24:1 | 24:1 | 32:1 | 32:1 | |
Optional No. 2 | — | — | 12:1 | 12:1 | — | — | — | — | — | |
Travel per Worm Turn (mm) | Standard | 0.60 | 1.00 | 1.00 | 1.50 | 1.50 | 1.50 | 1.50 | 1.50 | 1.50 |
Optional No. 1 | — | 0.25 | 0.25 | 0.38 | 0.50 | 0.50 | 0.50 | 0.50 | 0.50 | |
Optional No. 2 | — | — | 0.50 | 0.75 | — | — | — | — | — | |
Worm Torque at No Load (N-m) | Standard | 0.23 | 0.56 | 0.56 | 1.13 | 2.26 | 2.26 | 3.39 | 5.65 | 11.3 |
Optional No. 1 | — | 0.56 | 0.56 | 1.13 | 2.26 | 2.26 | 3.39 | 5.65 | 11.3 | |
Optional No. 2 | — | — | 0.56 | 1.13 | — | — | — | — | — | |
Maximum Input Power (kW) | Standard | 0.25 | 0.37 | 1.49 | 2.98 | 3.73 | 3.73 | 3.75 | 6.00 | 11.2 |
Optional No. 1 | — | 0.198 | 0.37 | 0.56 | 1.12 | 1.12 | 1.12 | 1.86 | 4.50 | |
Optional No. 2 | — | — | 0.56 | 1.49 | — | — | — | — | — | |
Worm Torque at Full Load (N-m) | Standard | 2.83 | 7.53 | 20.10 | 56.78 | 117.1 | 189.2 | 275.4 | 505.7 | 915.5 |
Optional No. 1 | — | 3.69 | 9.34 | 27.06 | 63.2 | 101.4 | 147.7 | 305.3 | 520.5 | |
Optional No. 2 | — | — | 12.8 | 36.65 | — | — | — | — | — | |
Efficiency Rating (%) | Standard | 16.9 | 21.1 | 19.8 | 21.0 | 20.4 | 18.9 | 17.3 | 14.2 | 13.0 |
Optional No. 1 | — | 10.8 | 10.7 | 11.0 | 12.6 | 11.8 | 10.8 | 7.8 | 7.6 | |
Optional No. 2 | — | — | 15.5 | 16.3 | — | — | — | — | — | |
Weight with 25mm Raise (kg) | 1.04 | 2.27 | 7.71 | 15.88 | 23.59 | 29.94 | 42.18 | 100 | 173 | |
Weight per Additional 25mm Raise (kg) | 0.04 | 0.13 | 0.13 | 0.40 | 0.63 | 0.67 | 1.16 | 1.65 | 2.46 | |
Key Torque (M-n) | 8.48 | 22.80 | 76.61 | 213.37 | 579.94 | 943.98 | 1374.01 | 2954.25 | 5746.55 | |
Maximum Worm Speed at Full Load (RPM) |
Standard | 844 | 469 | 708 | 501 | 304 | 188 | 129 | 113 | 117 |
Optional No. 1 | — | 491 | 378 | 198 | 169 | 105 | 72 | 58 | 83 | |
Optional No. 2 | — | — | 418 | 388 | — | — | — | — | — | |
Maximum Load at Full Horsepower and 1750 RPM (lb) |
Standard | 2.73 | 2.69 | 11.84 | 16.62 | 19.42 | 17.90 | 15.57 | 20.32 | 34.54 |
Optional No. 1 |
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2.21 | 5.34 | 4.93 | 8.40 | 7.74 | 5.52 | 6.61 | 18.01 | |
Optional No. 2 | — | — | 6.39 | 12.22 | — | — | — | — | — | |
Note: For loads from 25% to 100% of actuator capacity, torque requirements are approximately proportional to the load. Raises, measured in increments of 25mm, are available up to 6.1 meters, depending on lifting screw diameter and available bar stock length. Note: Contact customer service for motorized performance. |