Stainless Steel Jacks Quick Reference

MODEL Gear Ratio Capacity (tons) Lifting Screw Dia (in) Screw Lead (in) Root Dia (in) Turns of Worm for 1" Travel Max Input Torque (in - lb) Max Input (hp) Max Worm Speed at Rated Load (rpm) Max Load at 1,750 rpm (lb) Torque to Raise 1 lb. (in-lb) Tare Drag Torque (in-lb)
2SS-MSJ 6:1 0.66 1 .250 .698 24 33 2 1,800 1,320 .0250 4
24:1 0.66 1 .250 .698 96 14 12 1,800 1,320 .0150 4
5SS-MSJ 6:1 1.67 112 .375 1.066 16 125 3 1,510 2,873 .0376 10
24:1 1.67 112 .375 1.066 64 48 34 985 1,875 .0144 10
10SS-MSJ 8:1 3.33 2 .500 1.410 16 251 5 1,255 4,775 .0377 20
24:1 3.33 2 .500 1.410 48 128 112 739 4,813 .0192 20
15SS-MSJ 8:1 5.00 214 .500 1.684 16 407 5 774 4,424 .0407 20
24:1 5.00 214 .500 1.684 48 218 112 434 2,478 .0218 20
20SS-MSJ 8:1 6.66 212 .500 1.908 16 580 5 540 4,140 .0435 40
24:1 6.66 212 .500 1.908 48 291 112 325 2,478 .0218 40
25SS-MSJ 1023:1 8.30 3 .667 2.287 16 903 11 768 8,764 .0452 50
32:1 8.30 3 .667 2.287 48 471 312 468 5,364 .0235 50
35SS-MSJ 1023:1 11.66 334 .667 3.0 16 1,150 11 603 8,035 .0493 50
32:1 11.66 334 .667 3.0 48 600 312 368 5,022 .0251 50

NOTES:

  1. The recommended maximum speed is 1,800 rpm provided that the recommended horsepower and temperature are not exceeded.
  2. Input torque is shown as torque to lift one pound of load. Starting Torque is 100% greater than torque shown. Tare drag torque should be added for all loads.
  3. Maximum allowable horsepower ratings are based on a 25% duty cycle. For operation at higher duty cycles or repeated use over any segment of the total travel, temperature must be monitored and remain less than 200°F.
  4. Overload capacity of the Stainless Steel Machine Screw Jack is as follows: 10% for dynamic loads, 30% for static loads.
  5. Stainless Steel Machine Screw Jacks having gear ratios between 20:1 and 32:1, are self-locking and will hold loads without backdriving in the absence of vibration. All other ratios may require a brake to prevent backdriving.
  6. All units are suitable for intermittent operation providing that the housing temperature including ambient is not lower than -20°F. or higher than +200°F. Factory supplied grease in standard units will operate in this range. For higher or lower operating temperature ranges consult Nook Industries.
  7. Accessories such as boots, top plates and clevises are available.
  8. Catalog dimensions are representative only and are subject to change without notice. For construction, use only certified prints.
  9. Units are not to be used as personnel support or movement.
  10. End-of-travel stops are not provided.
  11. For greater capacity, specify a 17-4PH hardened worm.
  12. Tare drag torque need only be added if operating under 25% rated load.
  13. Horsepower per jack = Torque to raise 1 pound × Number of pounds to be raised × rpm
    63,025
  14. Starting Torque is 100% greater than torque shown.
Figure 1