- Available for machine screw jacks
- Available for metric (trapezoidal) jacks
- Limits lifting screw movement
- Anti-backlash Devices
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.
Parts list and exploded views are included in the O&M Manual. The serial number is attached to the product housing.

Click here for 2D & 3D
Click on the part number to reveal additional informaton about jack designs and shaft codes.
| 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).
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U=Upright |
I=Inverted |
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1=T1 |
2=T2 |
3=T3 |
4=T4 |
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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.
Rise is travel expressed in inches and not the actual screw length.
Left Side Shaft Code |
Right Side Shaft Code |
|
XXXX=Remove |
XXXX=Remove |
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.
CNT0=0.001" Increments
Note: Contact Joyce/Dayton for availability and options.
HW04=4" dia
HW06=6" dia
HW08=8" dia
HW10=10" dia
HW12=12" dia
POTA=0-10V (IP65)
POTB=4-20MA (IP65)
POTC=0-10V w/2 switches*
POTD=4-20MA w/2 switches*
*Optional IP65 rating available
ENCX=Encoder
ELS2=2 Position Electronic Switch
ELS4=4 Position Electronic Switch
ELS6=6 Position Electronic Switch
| 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 |
Ordering Example:
MMA A (Motor code from chart above)
MMA=56C
MMB=140TC
MMC=180TC
MMD=210TC
Standard motor adapters are aluminum
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. |
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| LS9-507 | LH | ||||||||||
| 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 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.