Machine Screw Jacks
About Machine Screw Jacks
Joyce worm gear machine screw jacks lift and precisely position loads (250 pounds to 250 tons). Upright or inverted jacks operate at full capacity in tension or compression. WJ and RWJ, single lead jacks are self-locking. DWJ and DRWJ, double lead jacks offer increased travel speed and require a brake or external locking device to hold position.
- Alloy steel input shafts
- Aluminum bronze wormgears
- Tapered or ball thrust bearings provide rugged reliability
- Double input shafts standard
- Protective boots available
- Anti-backlash devices available
- Customized mechanical jacks can be made to your specifications
- Custom finishes available
Parts list and exploded views are included in the O&M Manual. The serial number is attached to the product housing.
Joyce/Dayton provides motor controls ranging from simple Motor Starters to complex positioning systems and Custom controls. Every system that is powered by an electric motor requires a control system. At Joyce, we know that choosing the best option can sometimes be a challenge. That’s why our Engineers are available to help you through the process.
Product Media
Available Models
Boots and special finishes are available for Joyce Screw jacks. Choose from a variety of boot materials and designs for the jacks you select (translating, keyed, or KFTN). Joyce offers premium finishes, outdoor paint process, and custom finishes to meet your specifications. We have a hassle-free process for delivering what you need.
What You Need To Know To Specify Screw Jacks In Industrial Application
Jacks are rated based on their static thrust capacity from 250-pounds to 250-tons. But the selection of the best jack for the application requires further consideration.
1. When jacks are loaded in compression one must consider the load carrying capacity of the lifting screw (column load). How high do you need to lift the load? Choose a jack whose lifting screw is stout enough to handle the load at full rise.
2. Consider the travel speed of the DYNAMIC load. The speed at which the load will be moved is a limiting factor. How fast do you need to move the load? Sometimes double lead machine screw jacks or ball screw jacks are a better choice in a given application.
3. How frequently will the jack need to move the load? Remember that heat builds up between the machine screw and nut during normal operation. Duty cycles for machine screw jacks must include periods of rest to dissipate that heat.
Which Jack Design Is Best For Your Application?
Once loads, duty cycles, and travel speeds are established, designers must select which of the three jack design to use.
1. Translating Design Jacks are most often selected. With this design, a driven input worm acts on an internal worm gear causing the lifting screw to extend or retract. Operation requires that rotation of the lifting screw be prevented. This rotation it restrained whenever two or more jacks are tied to the same load.
2. Keyed Design Jacks are used any time rotation of the lifting screw is not restrained. For instance, when you must lift the jack to meet a load. This is how they work: A key, fixed to the jack housing and inserted into a keyway milled into the length of the lifting screw forces the lifting screw to translate without rotating.
3. Keyed For Travelign Nut Design Jacks (KFTN) are another option. These jacks have a fixed length lifting screw that rotates. Loads are attached to a flanged “traveling” nut that translates up and down the length of the rotating screw. This type of jack is ideal for applications that cannot accommodate a screw protection tube or that require a flush mount.
Take The Work Out Of Using Screw Jacks In Systems
Joyce/Dayton screw jacks and lifting systems offer wide-ranging lifting and positioning solutions for diverse industries. Our robust jacks reliably move and accurately position loads up to 250-tons. Joyce configures jacks with components such as motors, gear reducers, shafting, coupling, and motion control devices to create complete multi-jack systems.
Tell us what you need or use our exclusive JAX® Online software (it’s free). We will put together complete systems with single or multiple screw jacks for you. The software is great because it calculates motor horsepower and shaft diameters and torques. There are several common arrangements, but you can design your own.
Look for our next generation JAX® Online browser-based software soon.
Where Are Worm Gear Machine Screw Jacks Used?
Worm gear machine screw jacks are the workhorses of the lifting industry, available in static capacities up to 250-tons. They are commonly used to lift, hold, and position loads. Examples include: Platform lifts, Damper adjustments, Ergonomic lifts, Maintenance lifts, Roll adjustments, Earth Station Antennas, Drilling equipment, Solar Trackers, Conveyor adjustments, Packaging equipment, Gate adjustments, Dam adjustment, and Mine door openers.
Anti-Backlash Devices
- Available for machine screw jacks
- Available for metric (trapezoidal) jacks
- Limits lifting screw endplay
- Anti-backlash Devices
Encoders
- Standard 200 or 1024 PPR
- Quadrature wave form
- Stainless steel encoder
- Absolute encoder
- Encoders
Finishes
- Enamel finish (standard)
- Epoxy finish
- STEEL IT® epoxy
- Outdoor paint process
- Custom finishes available
- Anodized (250-lb to 1-ton)
- Nickel, Xylan®, Armoloy®
- Finishes
Follower Nuts
- For KFTN jack
- For translating jack
Input Shaft (worm)
- Square or hex to fit tool
- Special lengths
- 17-4 stainless steel available
- Metric diameters available
- One side can be cut off
- Other modifications available
- Input shaft cover available
Limit Switches
- Rotary cam (2-4 switches)
- SPDT standard
- DPDT available
- Explosion proof available
- Limit Switches
Lubrication
- Standard grease temperature range (40°F to 220°F)
- Low temperature option
- High temperature option
- Food grade option
Machine Screws
- Right hand thread standard
- Left hand thread available on many models
- Special material available
- Special pitch/lead available
- Special finishes available
- Special machining options
- Special end conditions available
Motor Mounts
- NEMA mounts available on 2-ton to 20-ton wormgear jacks and electric cylinders
- NEMA mounts included on integrated actuators
- Servo motor mounts available on 2-ton to 10-ton jacks and electric cylinders, special mounts available
- Custom mounts available
- Motor Mounts and Stock Motors
Potentiometers
- 0-10V (POTA)
- 4-20mA (POTB)
- 0-10V with limit switches (POTC)
- 4-20mA with limit switches(POTD)
- IP65
- Potentiometers
Protective Boots
- Protection from dirt and dust
- Guard against moisture
- Guard against corrosive contaminants
- Neoprene coated nylon (std)
- Special materials available
- Boot Material Chart
- Protective Boots
Screw Stops
- Standard on ComDRIVEs
- Adjustable
- Bolt- on
Thrust Rings
- Used in applications where static loads exceed jack capacity
Wormgear Sets
- Right hand gear set standard
- Left hand available on many models
- 25:1 ratio option available on several models
Sample Part Number:
Click on the part number to reveal additional informaton about jack designs and shaft codes.
Model Number
| Miniature | 1-Ton | 2-Ton | 2-Ton Reverse Base | 3-Ton | 5-Ton | 10-Ton | 15-Ton | 20-Ton |
|---|---|---|---|---|---|---|---|---|
| WJ250 WJ500* WJ1000 |
WJ51 WJ201 |
WJT62 WJT122 WJT242 WJT252 |
RWJT62 RWJT122 RWJT242 RWJT252 |
WJ63 WJ123 WJ243 WJ253 |
WJT65 WJT125 WJT245 WJT255 |
WJ810 WJ2410 WJ2510 |
WJ815 WJ2415 WJ2515 |
WJ820 WJ2420 WJ2520 |
| DWJ62* DWJ122* DWJ242* |
DRWJ62* DRWJ122* DRWJ242* |
DWJ63* DWJ123* DWJ243* |
DWJ65* DWJ125* DWJ245* |
DWJ810* DWJ2410* |
DWJ815* DWJ2415* |
DWJ820* DWJ2420* |
||
| 25-Ton | 30-Ton | 35-Ton | 50-Ton | 50-Ton Reverse Base | 75-Ton | 100-Ton | 150-Ton | 250-Ton |
| WJ1125 WJ3225 |
WJ1130 WJ3230 |
WJ1135 WJ3235 |
WJT1150 WJT3250 |
RWJT1150 RWJT3250 |
WJ1175 WJ3275 |
WJ12100 WJ36100 |
WJ12150 WJ36150 |
WJ50250 |
| DWJ1125* DWJ3225* |
DWJ1130* DWJ3230* |
Important Note: *Not self-locking, may lower under load. Brake motors or external locking systems are recommended.
D: Double Lead Screw
R: Reverse Base Jack, (only available on 2-ton and 50-ton jacks).
Jack Configuration
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U=Upright |
I=Inverted |
End Conditions
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1=T1 |
2=T2 |
3=T3 |
4=T4 |
Jack Designs
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S=Translating |
K=Keyed for Non Rotation |
N=Traveling Nut |
D=Double Clevis |
R=KFTN Trunnion* |
* Standard trunnion mounts available on 2-ton through 20-ton jacks.
Machine Screw Jack Rise
Rise is travel expressed in inches and not the actual screw length.
Left Side Shaft Code |
Right Side Shaft Code |
|
XXXX=Remove |
XXXX=Remove |
Optional Shaft Codes
Screw Stops and Boots
Screw stops are optional on machine screw jacks. When specified, the closed height of the jack and/or the protection tube length may be increased. When boots are added to machine screw jacks, the closed height of the jack may be increased.
Mechanical Counters
CNT0=0.001" Increments
Note: Contact Joyce/Dayton for availability and options.
Hand Wheels
HW04=4" dia
HW06=6" dia
HW08=8" dia
HW10=10" dia
HW12=12" dia
Geared Potentiometers
POTA=0-10V (IP65)
POTB=4-20MA (IP65)
POTC=0-10V w/2 switches*
POTD=4-20MA w/2 switches*
*Optional IP65 rating available
Encoders and Electronic Liit Switches
ENCX=Encoder
ELS2=2 Position Electronic Switch
ELS4=4 Position Electronic Switch
ELS6=6 Position Electronic Switch
Motor for Systems and Direct Drives
- All standard motors are 3-phase, 208-230/460 VAC or 230/460 VAC. Other motor options are available. Specify the appropriate motor size from the chart on the right.
- Refer to the "Additional Options" chart on the preceding page as needed.
- Brake motors (M2) are recommended for jacks that are not self-locking, and jacks with double lead screws.
- If the motor frequency will be varied to provide a "soft" start an inverter duty motor may be required.
Motors
| Size | Code |
|---|---|
| 1/4 HP | K |
| 1/3 HP | A |
| 1/2 HP | B |
| 3/4 HP | C |
| 1 HP | D |
| 1-1/2 HP | E |
| 2 HP | F |
| 3 HP | L |
| 5 HP | G |
| 7-1/2 HP | H |
| 10 HP | I |
| 15 HP | J |
Motor Mounts
Ordering Example:
MMA A (Motor code from chart above)
MMA=56C
MMB=140TC
MMC=180TC
MMD=210TC
Standard motor adapters are aluminum
Mechanical Limit Switches
Ordering Example:
LA (Models) 1(Number of DPDT Switches) 3(Available Positions)
| Model | Code | Available Positions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| LS7-402 | LI |
Number of DPDT Switches NOTE: Will always be 0 for LS7 models |
1 | 2* | 3 | 4 | 5 | 6* | 7 | 8 | |
| LS8-402 | LA | Left Side Shaft Options |  |
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| LS8-504 | LB | ||||||||||
| LS9-502 | LC | ||||||||||
| LS9-503 | LD | Right Side Shaft Options |  |
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| LS9-504 | LE | ||||||||||
| LS9-505 | LF | ||||||||||
| LS9-506 | LG |
*These positions are not standard. Contact Joyce/Dayton with your requirements. |
|||||||||
| LS9-507 | LH | ||||||||||
Additional Options
- X=Standard Jack, no additional options
- S=Additional Specification Required (comment as necessary)
Anti-Backlash
- A=Split Nut
- A90=A90 Design
- A95=A95 Design
Protective Boots
- B=Protective Boot
- D=Dual Protective Boot
Finishes
- F1=Do Not Paint
- F2=Epoxy Paint
- F3=Outdoor Paint Process
Motor Options
- M1=Less Motor
- M2=Brake Motor
- M3=Single Phase Motor (120VAC)
- M4=50Hz Motor
Grease/Seals
- H1=High Temperature Operation
- H2=Food Grade
Screw Stops
- ST0=Extending
- ST1=Retracting
- ST2=Both
- Specify as many options as needed
| MODEL | CPTY | SCRW DIAM (INCH) | THRD PITCH/ LEAD | WORM GEAR RATIO | WORM SHAFT TURNS FOR 1" TRAVEL | TARE TORQUE (INCH LBS.) | STARTING TORQUE (INCH LBS.) | OPERATING TORQUE (INCH LBS.) | EFFICIENCY RATING % APPROX. |
SCREW TORQUE (INCH LBS.) | BASIC JACK WEIGHT (LBS). | JACK WEIGHT PER INCH TRAVEL (LBS.) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WJ250 | 250 lbs. | 1/2 | .125 pitch STUB ACME |
5:1 | 40 | 1 | .025W* | .018W* @ 500 RPM | 23.0 | .050W* | 1.2 | 0.1 |
| WJ500 | 500 lbs. | 5/8 | .125 pitch/.250 lead STUB ACME |
5:1 | 20 | 1 | .041W* | .030W* @ 500 RPM | 27.2 | .079W* | 1.3 | 0.1 |
| WJ1000 | 1,000 lbs. | 5/8 | .125 pitch STUB ACME |
5:1 | 40 | 1 | .030W* | .021W* @ 500 RPM | 19.9 | .059W* | 1.3 | 0.1 |
| WJ51 | 1 ton | 3/4 | .200 pitch ACME 2C |
5:1 | 25 | 3 | .038W* | .026W* @ 500 RPM | 25 | .075W* | 6 | 0.3 |
| WJ201 | 1 ton | 3/4 | .200 pitch ACME 2C |
20:1 | 100 | 3 | .017W* | .009W* @ 500 RPM | 15.9 | .075W* | 6 | 0.3 |
| (R)WJT62 | 2 ton | 1 | .250 pitch ACME 2C |
6:1 | 24 | 4 | .041W* | .028W* @ 500 RPM | 24.2 | .098W* | 15 | 0.3 |
| (R)WJT122 | 2 ton | 1 | .250 pitch ACME 2C |
12:1 | 48 | 4 | .025W* | .015W* @ 500 RPM | 22.0 | .098W* | 15 | 0.3 |
| (R)WJT242 | 2 ton | 1 | .250 pitch ACME 2C |
24:1 | 96 | 4 | .018W* | .009W* @ 500 RPM | 18.3 | .098W* | 15 | 0.3 |
| (R)WJT252 | 2 ton | 1 | .250 pitch ACME 2C |
25:1 | 100 | 4 | .015W* | .0085W* @ 500 RPM | 17.0 | .098W* | 15 | 0.3 |
| D(R)WJ62 | 2 ton | 1 | .250 pitch .500 lead ACME 2C |
6:1 | 12 | 4 | .057W* | .039W* @ 500 RPM | 33.7 | .139W* | 15 | 0.3 |
| D(R)WJ122 | 2 ton | 1 | .250 pitch .500 lead ACME 2C |
12:1 | 24 | 4 | .035W* | .022W* @ 500 RPM | 30.5 | .139W* | 15 | 0.3 |
| D(R)WJ242 | 2 ton | 1 | .250 pitch .500 lead ACME 2C |
24:1 | 48 | 4 | .025W* | .013W* @ 500 RPM | 25.4 | .139W* | 15 | 0.3 |
| WJ63 | 3 ton | 1 | .250 pitch ACME 2C |
6:1 | 24 | 6 | .040W* | .029W* @ 500 RPM | 24.3 | .098W* | 17 | 0.4 |
| WJ123 | 3 ton | 1 | .250 pitch ACME 2C |
12:1 | 48 | 6 | .025W* | .016W* @ 500 RPM | 22.2 | .098W* | 17 | 0.4 |
| WJ243 | 3 ton | 1 | .250 pitch ACME 2C |
24:1 | 96 | 6 | .017W* | .009W* @ 500 RPM | 18.5 | .098W* | 17 | 0.4 |
| WJ253 | 3 ton | 1 | .250 pitch ACME 2C |
25:1 | 100 | 6 | .0155W* | .009W* @ 500 RPM | 17.8 | .098W* | 17 | 0.4 |
| DWJ63 | 3 ton | 1 | .250 pitch .500 lead ACME 2C |
6:1 | 12 | 6 | .055W* | .041W* @ 500 RPM | 33.8 | .139W* | 17 | 0.4 |
| DWJ123 | 3 ton | 1 | .250 pitch .500 lead ACME 2C |
12:1 | 24 | 6 | .034W* | .022W* @ 500 RPM | 30.7 | .139W* | 17 | 0.4 |
| DWJ243 | 3 ton | 1 | .250 pitch .500 lead ACME 2C |
24:1 | 48 | 6 | .024W* | .013W* @ 500 RPM | 25.6 | .139W* | 17 | 0.4 |
| WJT65 | 5 ton | 1 ½ | .375 pitch STUB ACME |
6:1 | 16 | 10 | .065W* | .044W* @ 300 RPM | 23.0 | .151W* | 32 | 0.7 |
| WJT125 | 5 ton | 1 ½ | .375 pitch STUB ACME |
12:1 | 32 | 10 | .041W* | .025W* @ 300 RPM | 20.6 | .151W* | 32 | 0.7 |
| WJT245 | 5 ton | 1 ½ | .375 pitch STUB ACME |
24:1 | 64 | 10 | .029W* | .015W* @ 300 RPM | 16.7 | .151W* | 32 | 0.7 |
| WJT255 | 5 ton | 1 ½ | .250 pitch ACME 2C |
25:1 | 100 | 10 | .022W* | .011W* @ 300 RPM | 13.4 | .131W* | 32 | 0.7 |
| DWJ65 | 5 ton | 1 ½ | .250 pitch .500 lead ACME 2C |
6:1 | 12 | 10 | .072W* | .050W* @ 300 RPM | 26.8 | .171W* | 32 | 0.7 |
| DWJ125 | 5 ton | 1 ½ | .250 pitch .500 lead ACME 2C |
12:1 | 24 | 10 | .045W* | .028W* @ 300 RPM | 23.9 | .171W* | 32 | 0.7 |
| DWJ245 | 5 ton | 1 ½ | .250 pitch .500 lead ACME 2C |
24:1 | 48 | 10 | .033W* | .017W* @ 300 RPM | 19.6 | .171W* | 32 | 0.7 |
| WJ810 | 10 ton | 2 | .500 pitch ACME 2C |
8:1 | 16 | 20 | .061W* | .043W* @ 200 RPM | 23.1 | .195W* | 43 | 1.3 |
| WJ2410 | 10 ton | 2 | .500 pitch ACME 2C |
24:1 | 48 | 20 | .030W* | .018W* @ 200 RPM | 18.8 | .195W* | 43 | 1.3 |
| WJ2510 | 10 ton | 2 | .250 pitch ACME 2C |
25:1 | 100 | 20 | .024W* | .014W* @ 200 RPM | 11.3 | .161W* | 43 | 1.3 |
| DWJ810 | 10 ton | 2 | .333 pitch .666 lead ACME 2C |
8:1 | 12 | 20 | .070W* | .062W* @ 200 RPM | 31.9 | .228W* | 43 | 1.3 |
| DWJ2410 | 10 ton | 2 | .333 pitch .666 lead ACME 2C |
24:1 | 36 | 20 | .035W* | .026W* @ 200 RPM | 25.9 | .228W* | 43 | 1.3 |
| WJ815 | 15 ton | 2 ¼ | .500 pitch ACME 2C |
8:1 | 16 | 30 | .069W* | .047W* @ 200 RPM | 21.1 | .210W* | 59 | 1.4 |
| WJ2415 | 15 ton | 2 ¼ | .500 pitch ACME 2C |
24:1 | 48 | 30 | .036W* | .020W* @ 200 RPM | 16.6 | .210W* | 59 | 1.4 |
| WJ2515 | 15 ton | 2 ¼ | .250 pitch ACME 2C |
25:1 | 100 | 30 | .026W* | .015W* @ 200 RPM | 10.2 | .178W* | 59 | 1.4 |
| DWJ815 | 15 ton | 2 ¼ | .333 pitch .666 lead ACME 2C |
8:1 | 12 | 30 | .079W* | .058W* @ 200 RPM | 34.4 | .244W* | 59 | 1.4 |
| DWJ2415 | 15 ton | 2 ¼ | .333 pitch .666 lead ACME 2C |
24:1 | 36 | 30 | .041W* | .025W* @ 200 RPM | 27.0 | .244W* | 59 | 1.4 |
| WJ820 | 20 ton | 2 ½ | .500 pitch ACME 2C |
8:1 | 16 | 40 | .075W* | .051W* @ 200 RPM | 19.6 | .227W* | 77 | 1.9 |
| WJ2420 | 20 ton | 2 ½ | .500 pitch ACME 2C |
24:1 | 48 | 40 | .039W* | .022W* @ 200 RPM | 15.4 | .227W* | 77 | 1.9 |
| WJ2520 | 20 ton | 2 ½ | .250 pitch ACME 2C |
25:1 | 100 | 40 | .029W* | .016W* @ 200 RPM | 9.4 | .194W* | 77 | 1.9 |
| DWJ820 | 20 ton | 2 ½ | .375 pitch .750 lead ACME 2C |
8:1 | 10.67 | 40 | .088W* | .061W* @ 200 RPM | 24.5 | .272W* | 77 | 1.9 |
| DWJ2420 | 20 ton | 2 ½ | .375 pitch .750 lead ACME 2C |
24:1 | 32 | 40 | .046W* | .026W* @ 200 RPM | 19.3 | .272W* | 77 | 1.9 |
| WJ1125 | 25 ton | 3 ⅜ | .666 pitch STUB ACME |
11:1 | 16 | 50 | .088W* | .055W* @ 200 RPM | 18.3 | .313W* | 164 | 3.1 |
| WJ3225 | 25 ton | 3 ⅜ | .666 pitch STUB ACME |
32:1 | 48 | 50 | .053W* | .025W* @ 200 RPM | 13.5 | .313W* | 164 | 3.1 |
| DWJ1125 | 25 ton | 3 ⅜ | .562 pitch 1.125 lead ACME 2C |
11:1 | 9.5 | 50 | .106W* | .067W* @ 200 RPM | 25.1 | .384W* | 164 | 3.1 |
| DWJ3225 | 25 ton | 3 ⅜ | .562 pitch 1.125 lead ACME 2C |
32:1 | 28.5 | 50 | .063W* | .030W* @ 200 RPM | 18.6 | .384W* | 164 | 3.1 |
| WJ1130 | 30 ton | 3 ½ | .666 pitch ACME 2C |
11:1 | 16 | 60 | .088W* | .055W* @ 200 RPM | 18.3 | .313W* | 164 | 3.0 |
| WJ3230 | 30 ton | 3 ½ | .666 pitch ACME 2C |
32:1 | 48 | 60 | .052W* | .025W* @ 200 RPM | 13.5 | .313W* | 164 | 3.0 |
| DWJ1130 | 30 ton | 3 ½ | .5625 pitch 1.125 lead ACME 2C |
11:1 | 9.5 | 60 | .107W* | .067W* @ 200 RPM | 25.1 | .384W* | 164 | 3.0 |
| DWJ3230 | 30 ton | 3 ½ | .5625 pitch 1.125 lead ACME 2C |
32:1 | 28.5 | 60 | .064W* | .030W* @ 200 RPM | 18.6 | .384W* | 164 | 3.0 |
| WJ1135 | 35 ton | 3 ¾ | .666 pitch ACME 2C |
11:1 | 16 | 70 | .093W* | .057W* @ 200 RPM | 17.4 | .328W* | 240 | 3.4 |
| WJ3235 | 35 ton | 3 ¾ | .666 pitch ACME 2C |
32:1 | 48 | 70 | .055W* | .026W* @ 200 RPM | 12.9 | .328W* | 240 | 3.4 |
| (R)WJT1150 | 50 ton | 4 ½ | .666 pitch ACME 2C |
11:1 | 16 | 100 | .095W* | .063W* @ 150 RPM | 15.8 | .378W* | 387 | 6.1 |
| (R)WJT3250 | 50 ton | 4 ½ | .666 pitch ACME 2C |
32:1 | 48 | 100 | .050W* | .027W* @ 150 RPM | 12.4 | .378W* | 387 | 6.1 |
| WJ1175 | 75 ton | 5 | .666 pitch ACME 2C |
11:1 | 16 | 155 | .107W* | .067W* @ 150 RPM | 14.8 | .418W* | 610 | 6.5 |
| WJ3275 | 75 ton | 5 | .666 pitch ACME 2C |
32:1 | 48 | 155 | .056W* | .028W* @ 150 RPM | 11.7 | .418W* | 610 | 6.5 |
| WJ12100 | 100 ton | 6 | .750 pitch ACME 2C |
12:1 | 16 | 205 | .112W* | .072W* @ 90 RPM | 13.9 | .495W* | 1010 | 10.0 |
| WJ36100 | 100 ton | 6 | .750 pitch ACME 2C |
36:1 | 48 | 205 | .059W* | .031W* @ 90 RPM | 10.8 | .495W* | 1010 | 10.0 |
| WJ12150 | 150 ton | 7 | 1.00 pitch ACME 2C |
12:1 | 12 | 300 | .134W* | .084W* @ 90 RPM | 15.7 | .595W* | 1350 | 12.2 |
| WJ36150 | 150 ton | 7 | 1.00 pitch ACME 2C |
36:1 | 36 | 300 | .070W* | .037W* @ 90 RPM | 12.1 | .595W* | 1350 | 12.2 |
| WJ50250 | 250 ton | 9 | 1.00 pitch ACME 2C |
50:1 | 50 | 500 | .036W* @ 60 RPM | 8.8 | .711W* | 3415 | 21.0 |
Important Note: Series DWJ double lead and WJ500 screw jacks are not self-locking. Brake motors or external locking systems are recommended.
(R): Reverse Base Jack.
*W: Load in pounds.
Tare Torque: Initial torque to overcome seal and normal assembly drag. (This value must be added to starting torque or operating torque values.)
Starting Torque: Torque value required to start moving a given load (dissipates to operating torque values once the load begins moving).
Operating Torque: Torque required to continuously raise a given load at the input RPM listed. NOTE: If your actual input RPM is 20% higher or lower than the listed RPM, please refer to our JAX program to determine actual torque values at your RPM.
Screw Torque: Torque required to resist screw rotation (Translating Design Jacks) and traveling nut rotation (Keyed for Traveling Nut Design Jacks).
Lead: The distance traveled axially in one rotation of the lifting screw.
Pitch: The distance from a point on a screw thread to a corresponding point on the next thread, measured axially.
Note: This chart is provided as a reference only. For specific information such as column loading, allowable continuous travel, and performance factors please refer to JAX online software of contact joyce.