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Stainless Steel Screw Jacks

Screw Jacks

Stainless steel screw jacks offer superior corrosion resistance, making them ideal for use in harsh, wet, or corrosive environments. They are also known for their durability, long service life, and ability to handle heavy loads.

Free Application Analysis

Features & Benefits
  • Capacity
    From 2- to 100- tons.
  • Maximum Control
    Anti-backlash models available.
  • Corrosion Resistance
    Stainless steel screw jacks are highly resistant to oxidation and corrosion, making them suitable for use in harsh environments, including wet or corrosive conditions.
  • Clean Room Suitable
    Ideal for applications where hygiene and preventing contamination are critical.
  • Temperature Resistant 
    Stainless steel can withstand extreme temperatures, making it suitable for applications in high heat or cold.
  • Protected Gear Design
    Sealed gear cavity keeps water and other contaminants out.
  • Control Screw Rotation
    Available with keyed lifting screws for translating screw models.
  • Retrofit Applications
    They can be used to replace non-stainless steel actuators in existing systems.
  • Optional Special Features
    Closed heights, lifting screw ends, worm shaft extensions, lifting screw thread pitches, materials, stop nut, bellows boot.

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, lowerspeeds, 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.

Performance Specifications - Machine Screw Actuator Stainless Steel

Capacity (tons) - 17-4PH Worn

2

5

10

15

20

25

30

35

50

100

Capacity (tons) - 316 SSWorn

0.67

1.66

3.33

5.00

6.66

8.33

9.9

11.66

16.66

33.33

Lifting Screw

Diameter (in)

1

1-1/2

2

1-1/4

2-1/2

3

3

3-3/4

4-1/2

6

Pitch (Std. & Opt.)

0.250

0.375

0.500

0.500

0.500

0.666

0.666

0.666

0.666

0.750

Pitch (Numerical)

—

0.250

0.250

0.250

0.250

0.320

0.320

0.320

0.320

—

Type

ACME

ACME

ACME

ACME

ACME

ACME

ACME

ACME

Mod. Sq.

Mod. Sq.

Worm Gear Ratios

Standard

6:1

6:1

8:1

8:1

8:1

10-2/3:1

10-2/3:1

10-2/3:1

10-2/3:1

12:1

Optional No. 1

24:1

24:1

24:1

24:1

24:1

32:1

32:1

32:1

32:1

36:1

Optional No. 2

12:1

12:1

—

—

—

—

—

—

—

—

Numeric Ratio

25:1

25:1

25:1

25:1

25:1

32:1

32:1

32:1

32:1

—

Turns of Worm for

1 inch Stroke

Standard

24

16

16

16

16

16

16

16

16

16

Optional No. 1

100

67

50

50

50

48

48

48

48

48

Optional No. 2

50

33

—

—

—

—

—

—

—

—

Numeric Ratio

100

100

100

100

100

100

100

100

100

100

Worm Torque at No

Load (in-lb)

Standard

5

10

20

20

30

40

40

50

100

200

Optional No. 1

5

10

20

20

30

40

40

50

100

200

Optional No. 2

5

10

—

—

—

—

—

—

—

—

Numeric Ratio

5

10

20

20

30

40

40

50

100

200

Maximum Horsepower

per Actuator

Standard

2

4

5

5

5

8

8

8

15

25

Optional No. 1

1/2

3/4

1-1/2

1-1/2

1-1/2

1-1/2

1-1/2

1-1/2

6

11

Optional No. 2

3/4

2

—

—

—

—

—

—

—

—

Numeric Ratio

1/2

3/4

1-1/2

1-1/2

1-1/2

1-1/2

1-1/2

1-1/2

6

11

Worm Torque at Full Load* (in-lb)

17-4PH Worm

Standard

120

450

750

1430

2050

2700

2640

4000

7500

16000

Optional No. 1

50

185

400

820

1170

1700

1685

2400

4200

8600

Optional No. 2

75

275

—

—

—

—

—

—

—

—

Numeric Ratio

48

175

370

640

925

1500

1800

2411

4040

—

Worm Torque at Full Load* (in-lb)

316SS Worm

Standard

42

150

253

471

675

926

940

1366

2566

5466

Optional No. 1

19

66

141

276

394

593

600

833

1466

3000

Optional No. 2

27

95

—

—

—

—

—

—

—

—

Numeric Ratio

25

57

67

109

144

336

635

350

619

—

Efficiency Rating (%) - 17-4PH Worm

Standard

22.1

22.1

26.5

20.9

22.0

22.4

22.4

17.4

13.3

12.4

Optional No. 1

13.3

9.1

16.6

12.1

12.8

11.8

11.8

9.7

7.9

7.7

Optional No. 2

17.7

18.1

—

—

—

—

—

—

—

—

Numeric Ratio

13.3

9.1

8.6

7.5

6.9

5.3

5.3

4.6

3.9

—

Efficiency Rating (%) - 316SS Worm

Standard

20.3

21.1

25.1

20.3

18.8

17.9

17.9

17.0

12.9

12.1

Optional No. 1

10.9

12.0

15.0

11.5

10.7

9.3

9.3

9.3

7.5

7.4

Optional No. 2

15.5

16.8

—

—

—

—

—

—

—

—

Numeric Ratio

10.9

8.0

7.5

5.8

5.4

4.5

5.0

4.5

3.6

—

Key Torque (in-lb) - 17-4PH Worm

Std. & Opt.

460

1750

4700

7580

10625

14000

16800

26500

47110

118200

Numeric Ratio

460

1599

4077

6645

9369

11474

13770

18561

30970

—

Key Torque (in-lb) - 316SS Worm

Std. & Opt.

153

581

1565

2527

3538

4665

5600

8828

15697

39396

Numeric Ratio

211

460

551

959

1199

2328

2800

2358

4087

—

Weight with 6 inch Stroke (Raise) (lb)

17

35

52

66

93

160

160

240

410

1200

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

0.3

0.9

1.4

1.5

2.6

2.5

2.5

3.7

5.5

9.0

Note: For loads from 25% to 100% of actuator capacity, torque requirements are approximately proportional to the load. Contact Duff-Norton Customer Service for motorized performance.

Models

Stainless Steel Actuator Cut-Away Diagram
Stainless-Steel-Machine-Screw-model.jpg

2 to 100 Ton Capacity

  • Anti-backlash models available Upright and inverted rotating screw models with traveling nut available
  • Sealed gear capacity keeps water and other contaminant's out
  • Available with keyed lifting screws for translating screw models
  • Can be retrofitted into applications were Duff-Norton non-stainless steel actuators have previously been used