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Ball Screw Jacks

1/2-to-50-ton capacity. Ball Screw Jacks provide high efficiency and high speed in one linear positioning package. These actuators come in many standard models, or can be custom designed for any application up to 50 tons. The positive action of the low friction ball screw and nut design provides longer life at load and requires less power to achieve a specified thrust. Ball screw actuators can be used individually, in tandem or as part of a larger mechanical system. With lifts up to 20 feet, Duff-Norton Ball Screw actuators offer the perfect solution to many linear positioning applications.

Specifications

Performance 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.

Machine Screw Actuator Stainless Steel

Capacity (tons)

 1/2 1 2H 2 3 5 (HL) 5 10 (HL) 10 20 (HL) 20 25 50*

Max. Speed Cface Driven (in/min)

 — — 287.5 72.0 118.5 287.5 136.5 215.5 102.0 215.5 108.0 81.0 —

Max. Speed Red. Driven (in/min)

 —
—
 57.51 14.4 23.7 57.4 27.2 43 20.4 43.1 21.6 20.1 33.4
 

Lifting Screw

Diameter (in)

 5/8 3/4 1 1 1-11/64 1-1/2 1-1/2 1-1/2 1-1/2 2-1/4 2-1/4 3 4

Lead (in)

 0.200 0.200 1.000 0.250 0.413 1.000 0.474 1.000 0.474 1.000 0.500 0.660 1.000
 

Worm Gear Ratios

Standard

 5:1 5:1 6:1 6:1 6:1 6:1 6:1 8:1 8:1 8:1 8:1 10-2/3:1 10-2/3:1

Optional No. 1

 20:1 20:1 24:1 24:1 24:1 24:1 24:1 24:1 24:1 24:1 24:1 32:1 32:1

Optional No. 2

 — — 12:1 12:1 12:1 12:1 12:1 — — — — — —
 

Turns of Worm for 1 inch Stroke

Standard

 25 25 6 24 14.526 6 12.667 8 16.889 8 16 16.16 10.67

Optional No. 1

 100 100 24 96 58.106 24 50.667 24 50.667 24 48 48.48 32

Optional No. 2

 — — 12 48 29.053 12 25.334 — — — — — —
 

Worm Torque at No Load (in-lb)

Standard

 0.5 2 10 3 5 20 10 20 15 50 40 40 40

Optional No. 1

 0.5 2 10 3 5 20 10 20 15 50 40 40 40

Optional No. 2

 — — 10 3 5 20 10 — — — — — —
 

Maximum Horsepower
per Actuator

Standard

 1/3 1/2 2 2 2 4 4 5 5 5 5 8 15

Optional No. 1

 1/6 1/4 1/2 1/2 1/2 3/4 3/4 1-1/2 1-1/2 1-1/2 1-1/2 2-1/2 6

Optional No. 2

 — — 3/4 3/4 3/4 2 2 — — — — — —
 

Starting Worm Torque at Full Load (in-lb)

Standard

 10.5 22 180 50 110 500 200 800 350 1375 700 925 2700

Optional No. 1

 5.0 11 80 25 50 206 90 400 175 625 325 475 1500

Optional No. 2

 — — 110 30 68 300 145 — — — — — —
 

Running Worm Torque at Full Load (in-lb)

Standard

 9.5 21 160 45 100 410 180 700 300 1270 650 825 2200

Optional No. 1

 4.0 10 70 20 45 183 80 290 150 570 300 425 1200

Optional No. 2

 — — 100 25 60 270 125 — — — — — —
 

Efficiency Rating (%)

Standard

 67.0 60.6 66.3 58.9 65.7 64.7 69.8 56.8 62.8 62.7 61.2 59.7 67.8

Optional No. 1

 39.8 31.8 37.9 33.2 36.5 36.2 39.3 45.7 41.9 46.5 44.2 38.6 41.4

Optional No. 2

 — — 53.0 53.1 54.8 49.1 50.3 — — — — — —
 

Weight with 6 inch Stroke (Raise) (lb)

 2.8 5 20 20 21 40 40 50 50 115 115 235 520
 

Weight per Additional 1 inch Stroke (Raise) (lb)

 0.1 0.3 0.3 0.3 0.4 0.9 0.9 0.9 0.9 1.5 1.5 2.9 5.0
 

Hold Back Torque at Rated Load (ft-lb)

Standard

 1 1 2 2 7 8 8 24 11 24 24 24 32

Optional No. 1

 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 2 2 2 33

Optional No. 2

 — — 1 1 2 2 2 — — — — — —
 

Key Torque (in-lb)

 35 70 100 175 440 1800 850 3500 1700 7000 3500 6000 17700
 

Max Worm Speed at Full Load (rpm)

Standard

 2001 1432 700 2521 1146 504 1146 394 900 229 450 545 350

Optional No. 1

 2101 1432 394 1261 630 229 252 236 540 151 291 332 252

Optional No. 2

 — — 430 5875 695 420 869 — — — — — —
 

Maximum Load at Full Horsepower and 170 rpm (lb)

Standard

 1150 1601 1459 5875 3830 2585 6384 4104 9855 3927 8489 14018 17250

Optional No. 1

 1223 1556 458 2729 1734 377 2126 1791 4878 280 1968 5751 8942

Optional No. 2

 — — 680 3557 2096 1858 4595 — — — — — —

Notes:
- Hold Back Torque is restraining torque at the worm shaft to keep load from running down.
- Lifting torques are proportional to load, down to 25% of rated load.
- All actuator units can be supplied with standard raises up to 24 inches. Special raises up to 20 feet are available upon request. Closed height dimensions may increase for actuators supplied with bellows boots.
* Does your ball screw application require more than 50 tons? Please contact our Customer Service group to explore our specialty options for higher load ratings up to 100 tons.

Models

Ball Screw Actuator Cut-Away Diagram

Ball-Screw-Actuator.jpg