Machine Screw 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 Rase 1 lb. (in-lb) Tare Drag Torque (in-lb)
1-MSJ 5:1 1 34 .200 .502 25 45 12 700 800 .0225 3
20:1 1 34 .200 .502 100 21 14 750 857 .0105 3
2-MSJ 6:1 2 1 .250 .698 24 100 2 1,260 2,881 .0250 4
12:1 2 1 .250 .698 48 62 1 12 1,525 3,456 .0154 4
24:1 2 1 .250 .698 96 42 12 750 1,715 .0105 4
2R-MSJ 6:1 2 1 .250 .698 24 100 2 1,260 2,881 .0250 4
12:1 2 1 .250 .698 48 62 1 12 1,525 3,486 .0154 4
24:1 2 1 .250 .698 96 42 12 750 1,715 .0105 4
2.5-MSJ 6:1 2 12 1 .250 .698 24 126 2 1,000 2,858 .0252 5
12:1 2 12 1 .250 .698 48 74 1 12 1,277 3,650 .0148 5
24:1 2 12 1 .250 .698 96 53 12 594 1,699 .0106 5
5-MSJ 6:1 5 1 12 .375 1.066 16 376 3 500 2,873 .0376 10
24:1 5 1 12 .375 1.066 64 144 34 330 1,875 .0144 10
10-MSJ 8:1 10 2 .500 1,410 16 753 5 418 4,766 .0377 20
24:1 10 2 .500 1.410 48 384 1 12 246 2,813 .0192 20
15-MSJ 8:1 15 2 14 .500 1.684 16 1,221 5 258 4,424 .0407 20
24:1 15 2 14 .500 1.684 48 654 1 12 144 2,478 .0218 20
20-MSJ 8:1 20 2 12 .500 1.908 16 1,740 7 12 272 6,209 .0435 40
24:1 20 2 12 .500 1.908 48 873 2 12 180 4,130 .0218 40
30-MSJ 10 23:1 30 3 38 .667 2.652 16 2,710 11 256 8,764 .0452 50
32:1 30 3 38 .667 2.652 48 1,411 3 12 156 5,364 .0235 50
35-MSJ 35 3 34 .667 3.009 16 3,450 11 200 8,035 .0493 50
32:1 35 3 34 .667 3.009 48 1,800 3 12 122 4,904 .0257 50
50-MSJ 10 23:1 50 4 12 .667 3.782 16 5,555 16 181 10,382 .0555 100
32:1 50 4 12 .667 3.782 48 3,014 5 104 5,982 .0301 100
75-MSJ 10 23:1 75 5 .667 4.286 16 8,236 28 214 18,368 .0549 155
32:1 75 5 .667 4.286 48 3,780 9 150 12,862 .0252 155
100-MSJ 10 23:1 100 6 .667 5.254 16 13,166 32 153 17,330 .0665 205
32:1 100 6 .667 5.254 48 7,460 12 12 106 11,941 .0377 205

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. For loads less than 25% of rated loads add tare drag torque.
  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 Machine Screw Jack is as follows: 10% for dynamic loads, 30% for static loads.
  5. 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 vibrations. 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, Inc.
  7. Accessories such as boots, limit switches, 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. Tare drag torque need only be added if operating under 25% rated load.
  12. Starting Torque is 100% greater than torque shown.
  13. Measurements listed are for non-keyed jacks. See individual jack pages for keyed jack info.
Horsepower per jack = Torque to raise 1 pound × Number of pounds to be raised × rpm
63,025
Figure 1