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.
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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.
- 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
Input Shaft (Worm)
Standard input shaft extends to the right and left. Shaft modifications are available.
Sleeve (Housing):
Sleeve/Sleeve Cap Material
- 250-lb - 1-ton Aluminum
- 2-ton - 35-ton Ductile Iron
- 50-ton - 250-ton Steel
- Options:
- 2-ton Stainless Steel
- 5-ton - 25-ton Stainless Steel
- 5-ton - 35-ton Steel
Thrust Bearings:
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.
Protection Tube:
This tube shields the lifting screw from debris and damage as it retracts into the jack body.
Load Pad End Condition:
This provides a flat mounting surface, often with holes, at the tip of the lifting screw for attaching or supporting the load. Jack must be attached to load and rotation must be restrained. Keyed machine screw jacks are available (WJ 500 and larger)
Lifting Screw:
This is the main threaded shaft that moves vertically when driven by the worm gear, providing the linear motion to lift or lower the load.
Wormgear:
Internal threads which engage the main lifting screw, causing it to move up or down (translate) and lift or lower the load Made from aluminum bronze material.
Click the points on the Screw Jack diagram for an in-depth look at its components
- Screw Jacks Applications
How 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.
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 designs to use.
Translating Design Jacks
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.
Keyed Design Jacks
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.
Keyed For Traveling Nut Design Jacks (KFTN)
Keyed For Traveling 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.
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.
- Conveyor adjustments
- Dam adjustment
- Damper adjustments
- Drilling equipment
- Earth Station Antennas
- Ergonomic lifts
- Gate adjustments
- Maintenance lifts
- Mine door openers
- Packaging equipment
- Platform lifts
- Roll adjustments
- Solar Trackers
- Product Add-Ons
Hover the product options below to view more information
- Part & Model # Guide
Our easy-to-use JAX® Online software enables you to specify the right jacks and components for your ideal lifting and linear motion systems. You can start with a complete set of requirements, or just a few simple inputs, and let JAX® Online suggest the perfect components.
Each section of the part number refers to information about jack designs and shaft codes. Click the section of the part number below to get additional information on each section.
Sample Part #:
WJT65 U 1 N 18.5 STDX STDX B
- WJT65Model #
Model Number
Expand the sections below to find the model number(s) for that category.
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).
- UJack
ConfigurationJack Configuration
U=Upright
I=Inverted - 1End
ConditionsEnd Conditions
1=T1(plain end)
2=T2(load pad)
3=T3 (threaded end)
4=T4(male clevis) - NJack
DesignsJack Designs
S=Translating
K=Keyed for Non Rotation
N=Traveling Nut
D=Double Clevis
R=KFTN Trunnion*
T=Trunnion* - 18.5Machine Screw
Jack RiseMachine Screw Jack Rise
Rise is travel expressed in inches and not the actual screw length.
- STDX STDXLeft/ Right Side
Shaft CodeLeft/ Right Side Shaft Code
XXXX=Remove STDX=Standard
XXXX=Remove STDX=Standard - BAdditional
OptionsAdditional 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
- WJT65Model #
- Product Specifications
Product Media
Custom products are available. Contact us with your application's requirements.
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 ACME5:1 40 1 .025W* .018W* @ 500 RPM 23.0 .050W* 1.2 0.1 WJ500 500 lbs. 5/8 .125 pitch/.250 lead
STUB ACME5:1 20 1 .041W* .030W* @ 500 RPM 27.2 .079W* 1.3 0.1 WJ1000 1,000 lbs. 5/8 .125 pitch
STUB ACME5:1 40 1 .030W* .021W* @ 500 RPM 19.9 .059W* 1.3 0.1 WJ51 1 ton 3/4 .200 pitch
ACME 2C5:1 25 3 .038W* .026W* @ 500 RPM 25 .075W* 6 0.3 WJ201 1 ton 3/4 .200 pitch
ACME 2C20:1 100 3 .017W* .009W* @ 500 RPM 15.9 .075W* 6 0.3 (R)WJT62 2 ton 1 .250 pitch
ACME 2C6:1 24 4 .041W* .028W* @ 500 RPM 24.2 .098W* 15 0.3 (R)WJT122 2 ton 1 .250 pitch
ACME 2C12:1 48 4 .025W* .015W* @ 500 RPM 22.0 .098W* 15 0.3 (R)WJT242 2 ton 1 .250 pitch
ACME 2C24:1 96 4 .018W* .009W* @ 500 RPM 18.3 .098W* 15 0.3 (R)WJT252 2 ton 1 .250 pitch
ACME 2C25:1 100 4 .015W* .0085W* @ 500 RPM 17.0 .098W* 15 0.3 D(R)WJ62 2 ton 1 .250 pitch
.500 lead
ACME 2C6:1 12 4 .057W* .039W* @ 500 RPM 33.7 .139W* 15 0.3 D(R)WJ122 2 ton 1 .250 pitch
.500 lead
ACME 2C12:1 24 4 .035W* .022W* @ 500 RPM 30.5 .139W* 15 0.3 D(R)WJ242 2 ton 1 .250 pitch
.500 lead
ACME 2C24:1 48 4 .025W* .013W* @ 500 RPM 25.4 .139W* 15 0.3 WJ63 3 ton 1 .250 pitch
ACME 2C6:1 24 6 .040W* .029W* @ 500 RPM 24.3 .098W* 17 0.4 WJ123 3 ton 1 .250 pitch
ACME 2C12:1 48 6 .025W* .016W* @ 500 RPM 22.2 .098W* 17 0.4 WJ243 3 ton 1 .250 pitch
ACME 2C24:1 96 6 .017W* .009W* @ 500 RPM 18.5 .098W* 17 0.4 WJ253 3 ton 1 .250 pitch
ACME 2C25:1 100 6 .0155W* .009W* @ 500 RPM 17.8 .098W* 17 0.4 DWJ63 3 ton 1 .250 pitch
.500 lead
ACME 2C6:1 12 6 .055W* .041W* @ 500 RPM 33.8 .139W* 17 0.4 DWJ123 3 ton 1 .250 pitch
.500 lead
ACME 2C12:1 24 6 .034W* .022W* @ 500 RPM 30.7 .139W* 17 0.4 DWJ243 3 ton 1 .250 pitch
.500 lead
ACME 2C24:1 48 6 .024W* .013W* @ 500 RPM 25.6 .139W* 17 0.4 WJT65 5 ton 1 ½ .375 pitch
STUB
ACME6:1 16 10 .065W* .044W* @ 300 RPM 23.0 .151W* 32 0.7 WJT125 5 ton 1 ½ .375 pitch
STUB
ACME12:1 32 10 .041W* .025W* @ 300 RPM 20.6 .151W* 32 0.7 WJT245 5 ton 1 ½ .375 pitch
STUB
ACME24:1 64 10 .029W* .015W* @ 300 RPM 16.7 .151W* 32 0.7 WJT255 5 ton 1 ½ .250 pitch
ACME 2C25:1 100 10 .022W* .011W* @ 300 RPM 13.4 .131W* 32 0.7 DWJ65 5 ton 1 ½ .250 pitch
.500 lead
ACME 2C6:1 12 10 .072W* .050W* @ 300 RPM 26.8 .171W* 32 0.7 DWJ125 5 ton 1 ½ .250 pitch
.500 lead
ACME 2C12:1 24 10 .045W* .028W* @ 300 RPM 23.9 .171W* 32 0.7 DWJ245 5 ton 1 ½ .250 pitch
.500 lead
ACME 2C24:1 48 10 .033W* .017W* @ 300 RPM 19.6 .171W* 32 0.7 WJ810 10 ton 2 .500 pitch
ACME 2C8:1 16 20 .061W* .043W* @ 200 RPM 23.1 .195W* 43 1.3 WJ2410 10 ton 2 .500 pitch
ACME 2C24:1 48 20 .030W* .018W* @ 200 RPM 18.8 .195W* 43 1.3 WJ2510 10 ton 2 .250 pitch
ACME 2C25:1 100 20 .024W* .014W* @ 200 RPM 11.3 .161W* 43 1.3 DWJ810 10 ton 2 .333 pitch
.666 lead ACME 2C8:1 12 20 .070W* .062W* @ 200 RPM 31.9 .228W* 43 1.3 DWJ2410 10 ton 2 .333 pitch
.666 lead ACME 2C24:1 36 20 .035W* .026W* @ 200 RPM 25.9 .228W* 43 1.3 WJ815 15 ton 2 ¼ .500 pitch
ACME 2C8:1 16 30 .069W* .047W* @ 200 RPM 21.1 .210W* 59 1.4 WJ2415 15 ton 2 ¼ .500 pitch
ACME 2C24:1 48 30 .036W* .020W* @ 200 RPM 16.6 .210W* 59 1.4 WJ2515 15 ton 2 ¼ .250 pitch
ACME 2C25:1 100 30 .026W* .015W* @ 200 RPM 10.2 .178W* 59 1.4 DWJ815 15 ton 2 ¼ .333 pitch
.666 lead ACME 2C8:1 12 30 .079W* .058W* @ 200 RPM 34.4 .244W* 59 1.4 DWJ2415 15 ton 2 ¼ .333 pitch
.666 lead ACME 2C24:1 36 30 .041W* .025W* @ 200 RPM 27.0 .244W* 59 1.4 WJ820 20 ton 2 ½ .500 pitch
ACME 2C8:1 16 40 .075W* .051W* @ 200 RPM 19.6 .227W* 77 1.9 WJ2420 20 ton 2 ½ .500 pitch
ACME 2C24:1 48 40 .039W* .022W* @ 200 RPM 15.4 .227W* 77 1.9 WJ2520 20 ton 2 ½ .250 pitch
ACME 2C25:1 100 40 .029W* .016W* @ 200 RPM 9.4 .194W* 77 1.9 DWJ820 20 ton 2 ½ .375 pitch
.750 lead ACME 2C8:1 10.67 40 .088W* .061W* @ 200 RPM 24.5 .272W* 77 1.9 DWJ2420 20 ton 2 ½ .375 pitch
.750 lead ACME 2C24:1 32 40 .046W* .026W* @ 200 RPM 19.3 .272W* 77 1.9 WJ1125 25 ton 3 ⅜ .666 pitch STUB
ACME11:1 16 50 .088W* .055W* @ 200 RPM 18.3 .313W* 164 3.1 WJ3225 25 ton 3 ⅜ .666 pitch STUB
ACME32:1 48 50 .053W* .025W* @ 200 RPM 13.5 .313W* 164 3.1 DWJ1125 25 ton 3 ⅜ .562 pitch 1.125 lead
ACME 2C11:1 9.5 50 .106W* .067W* @ 200 RPM 25.1 .384W* 164 3.1 DWJ3225 25 ton 3 ⅜ .562 pitch 1.125 lead
ACME 2C32:1 28.5 50 .063W* .030W* @ 200 RPM 18.6 .384W* 164 3.1 WJ1130 30 ton 3 ½ .666 pitch
ACME 2C11:1 16 60 .088W* .055W* @ 200 RPM 18.3 .313W* 164 3.0 WJ3230 30 ton 3 ½ .666 pitch
ACME 2C32:1 48 60 .052W* .025W* @ 200 RPM 13.5 .313W* 164 3.0 DWJ1130 30 ton 3 ½ .5625 pitch 1.125 lead
ACME 2C11:1 9.5 60 .107W* .067W* @ 200 RPM 25.1 .384W* 164 3.0 DWJ3230 30 ton 3 ½ .5625 pitch 1.125 lead
ACME 2C32:1 28.5 60 .064W* .030W* @ 200 RPM 18.6 .384W* 164 3.0 WJ1135 35 ton 3 ¾ .666 pitch
ACME 2C11:1 16 70 .093W* .057W* @ 200 RPM 17.4 .328W* 240 3.4 WJ3235 35 ton 3 ¾ .666 pitch
ACME 2C32:1 48 70 .055W* .026W* @ 200 RPM 12.9 .328W* 240 3.4 (R)WJT1150 50 ton 4 ½ .666 pitch
ACME 2C11:1 16 100 .095W* .063W* @ 150 RPM 15.8 .378W* 387 6.1 (R)WJT3250 50 ton 4 ½ .666 pitch
ACME 2C32:1 48 100 .050W* .027W* @ 150 RPM 12.4 .378W* 387 6.1 WJ1175 75 ton 5 .666 pitch
ACME 2C11:1 16 155 .107W* .067W* @ 150 RPM 14.8 .418W* 610 6.5 WJ3275 75 ton 5 .666 pitch
ACME 2C32:1 48 155 .056W* .028W* @ 150 RPM 11.7 .418W* 610 6.5 WJ12100 100 ton 6 .750 pitch
ACME 2C12:1 16 205 .112W* .072W* @ 90 RPM 13.9 .495W* 1010 10.0 WJ36100 100 ton 6 .750 pitch
ACME 2C36:1 48 205 .059W* .031W* @ 90 RPM 10.8 .495W* 1010 10.0 WJ12150 150 ton 7 1.00 pitch
ACME 2C12:1 12 300 .134W* .084W* @ 90 RPM 15.7 .595W* 1350 12.2 WJ36150 150 ton 7 1.00 pitch
ACME 2C36:1 36 300 .070W* .037W* @ 90 RPM 12.1 .595W* 1350 12.2 WJ50250 250 ton 9 1.00 pitch
ACME 2C50:1 50 500 .036W* @ 60 RPM 8.8 .711W* 3415 21.0
