Screw Jack

What is a Screw Jack?

A is a gearbox assembly (either worm gear or bevel gear) and a transmission product (lead screw, ball screw or roller screw) which through use of a motor is used to convert rotary into linear motion. They can be used to push, pull, tension, lock, unlock, tilt, pivot, roll, slide and lift or lower loads, anything from a few kilos to thousands of tonnes.

A screw jack system includes essential components such as heavy-duty vertical screw or power screw (leadscrew) with a load table mounted on its top, a worm or bevel gearbox assembly, and a motor to provide rotary motion. The screw jack is operated by turning the vertical screw or power screw with the help of gear system and motor, to convert rotary motion into linear motion.

Types of Screw Jack

We mainly offer below types:


All kinds of custom-made screw jacks, like Stainless Steel Screw Jacks, double clevis screw jacks, heavy load screw jacks, etc.
Different types of screw jacks: translating, rotating, and keyed.

Plain Head Translating Screw Jack
Plain Head Translating Screw Jack
Clevis End Translating Screw Jack
Clevis End Translating Screw Jack
Flange End Translating Screw Jack
Flange End Translating Screw Jack

Worm Gear Screw Jacks

In addition to the low cost and self-locking characteristics, another advantage of worm gear screw jacks, and all screw jacks, is the mechanical advantage achieved through the internal gear ratio resulting in the ability to lift, lower, push or pull a significant load with a relatively small amount of torque on the I/O shaft. The most common jack is the worm gear screw jack, also referred to as machined screw jack because the acme, or trapezoidal, the lead screw is machined. Worm gear screw jacks are perfect in multiple jack systems because the torsional deflection of connecting shafts and couplings has little effect on the positioning. Under heavy load, worm gear screw jacks are not designed for high use or rich-duty cycle applications. They also suffer from low travel rates or speed and low efficiency. However, the lack of efficiency inherent in worm gearing produces the self-locking benefit associated with worm gear screw jacks.

Ball Screw Jacks

Ball screw jacks incorporate a ball screw instead of a machined screw and a ball nut, which activates the screw. The advantage of ball screw jacks and the rolling action of their design is greater efficiency, up to 50%, which is much greater than bevel gear jacks and worm gear jacks. Because of their efficiency, ball screw jacks can be used in heavier-duty cycle applications. They also provide good positional accuracy in high-speed applications. One potential disadvantage is that ball screw jacks are not self-locking and require a brake or motor with enough holding torque to prevent the I/O shaft from back-driving. Another unique feature of ball screw jacks is their ability to incorporate worm gearing or bevel gearing. Bevel gear ball screw jacks have efficiency ratings of about 50%. This gearing option provides another level of flexibility for automated lifting, lowering, pushing, or pulling applications requiring heavier duties cycles and positional accuracy at high speeds. Ball screw jacks are typically at the top of the screw jack pricing spectrum and can be a little tricky to maintain. Despite these issues, ball screw jacks might be the best choice for your project.

Bevel Gear Screw Jacks

Bevel gear screw jacks use the same trapezoidal or acme screws used in machined screw jacks to move the load. In keeping with their name, however, bevel gear jacks use bevel gears inside the housing instead of worm gearing. Bevel gears are more efficient than worm gearing—around 35% compared to 20%—and they have lower ratios that result in higher speeds and travel rates. Typically, bevel gear jacks maintain self-locking characteristics while providing higher travel speeds.

Another benefit of bevel gear jacks is their I/O shaft flexibility. They are available in single shaft, two shaft and three shaft configurations. In two and three shaft configurations the jack offers right angle characteristics with the ability to divide input power or torque, sending it equally in different directions. Flexibility in shaft configuration makes bevel gear jacks ideal for multiple jack configurations and can eliminate the need for stand-alone right angle gearboxes used in many worm gear jack systems.

Bevel gear screw jacks are well suited for light and moderate duty cycle applications and they are priced slightly above worm gear or machined screw jacks because of their greater efficiency, flexibility and speed characteristics. While a bit more expensive, bevel gear jacks reduce the number of required components in multiple jack systems, which helps balance the difference in price.

Application of Screw Jack

Screw jack lifts are the ideal product to push, pull, lift, lower and position object loads. They are essential components in automated machinery because of high reliability and synchronization. They usually operate in high-load applications. Additionally, screw jack is increasingly finding uses as alternatives to conventionally pneumatic and hydraulic systems, because it has better energy efficiency and greater levels of precision. Screw jacks and lifting systems offer wide-ranging lifting and positioning solutions for diverse industries. Here are some common screw jack uses, given below:

1. Assembling- This is used to assemble the vehicle parts while lifting the base of the vehicle up using a screw jack mechanism. This mechanism is also used in fixing errors in a vehicle like cars, trucks, buses etc.

2. Adjusting- This mechanism is also used in adjusting and moving heavyweights such as scaffolding pipes in various industries like civil and mechanical.

3. Holding- This mechanism is used in hold the heavy loads to replace the components inside.

4. Lifting- Lifting loads in the main specification of this mechanism in general such as heavy machinery, heavy-duty vehicles, car, trucks etc. A screw jack is a common mechanism to lift loads around the globe.

5. Stabilization- This mechanism is also used to stabilize the misaligned structures or components in most of the civil, mechanical and aircraft industries.

6. Pushing-Pulling- Pushing and pulling the horizontal stabilizers of the aircraft also comes under the use of a jackscrew.

7. Stage setup- This mechanism is also used in setting up the stage in various stage-related programmes such as music gatherings, political events etc.

8. Opening and closing- The same mechanism is used in opening and closing some types of gates such as shutters in shops or in heavy-weight gates.

9. Weight Measuring- The mechanism of the screw jack is used in weigh scale to lift heavy vehicles and calculate the overall loads in civil plants and mechanical industries.

Adjustable Screw Jack Performance Characteristics

The screw jack is an essential lifting component with a load capacity of 0.5-300T. The utility model has the advantages of compact structure, small volume, light weight, comprehensive power source, no noise, convenient installation, flexible use, and many functions. There are many advantages, such as multiple forms, high reliability, and long service life. It has many functions, such as lifting, landing, pushing, and flipping. It can be used in a single or combination and adjust the height of lifting or pushing according to a specific program. An electric motor or other power can directly drive it. It can also be manually operated with a maximum input speed of 1500r/min and a maximum lifting speed of 2.7m/min. There are different structural types and assembly methods, and the promotion height is customized according to the user's requirements.

Hydraulic Jack VS Screw Jack

Screw Jack and hydraulic jack are the jacks we often use. What's the difference between a screw jack and a hydraulic jack? A screw jack is also known as a mechanical jack. It uses a screw lift to transfer power. Like wrench bolts and nuts, it keeps screwing nuts, and the bolts will stretch out and retract.

Hydraulic Jack uses the Pascal principle and hydraulic oil to transfer power. A handle presses a small piston, and the small piston pushes the hydraulic oil to generate pressure. The hydraulic oil passes through the pipeline (invisible in this case) and enters the lower part of the big piston. The force of the hydraulic oil acts on the big piston and pushes the big piston upward, thus forming a great thrust (thrust = pressure x area). Keep pressing the small piston; the big piston will rise slowly. Open the relief ; the big piston can retract under gravity.

The screw jack is compact in structure, small in size, light in weight, and easy to carry. It is widely used in lifting operations of factories, warehouses, bridges, harbors, transportation, and construction engineering departments. A screw jack, also known as a mechanical jack, is driven by humans through the screw pair, with a screw or nut sleeve as lifting parts. Ordinary screw jack supports heavy objects by thread self-locking, which is simple in structure, but low in transmission efficiency and slow in return. Specification types of screw jacks are 3T screw jack, 5T screw jack, 8T screw jack, 10T screw jack, 16T screw jack, 20T screw jack, 25T screw jack, 32T screw jack, 50T screw jack, 50T screw jack, 100T screw jack, 200T screw jack, 320T screw jack. Rotary jack, 380T screw jack.

Professional Screw Jack Manufacturer & Supplier

With over ten years of professional manufacturing experience, our specialized workers always produce screw jacks with refined craftsmanship and consistent quality.

Whether working on large volume orders or simply 1 set, our standardized production process ensures you get the same level of high-quality screw jacks at a short lead time.

  • Well-trained Staffs
  • Extensive Manufacturing experience
  • Fully-equipped Production Workshop
  • Well-established manufacturing standard

Screw Jack Lifting Systems

(1) Screw Jack Lifting Systems are best in applications where you're lifting a load, but accuracy is not as critical as during the positioning, such as moving boxes from a floor to a mezzanine.
(2) Other applications for Screw Jack Lifting Systems include machine adjustment, conveyors, and ergonomic platforms.

Screw Jack Positioning System

Screw Jack Positioning Systems are used to position satellite dishes that require exact positioning on a target to pick up a signal and other applications that require high-precision movement.
(1) Screw Jack Positioning Systems are best in applications that require accuracy and precision. These systems are capable of push, pull, tilt, or rolling movements. Screw Jack Positioning Systems are used for positioning satellite dishes that require exact positioning on a target to pick up a signal and other applications that require a high level of precision movement.
(2) Screw Jack Positioning Systems are also used in applications such as metals manufacturing to keep a steel roll straight and balanced during the production process.

We have been manufacturing reliable, high-quality industrial screw jacks ranging from mini screw jacks to ACME screw jacks, and everything in between, since 1883. Our screw jacks are subjected to rigorous testing to assure maximum performance and quality for use in agriculture, aerospace, construction, and many other industries. In fact, our screw jacks are in use around the world in industries such as plastics, metals production, beverage bottling systems, aircraft assembly, paper production, e-commerce, and many other applications that move the world forward and improve lives.

Other Different Types of Screw Jack

There are a few screw jack design available including Translating, Keyed and Traveling Nut. All of them can be achieved with either a machine screw jack or ball screw jack. Want to know which jack design is best for your application? Below details may help you.

Translating Screw Jacks

Translating screw Jacks are most often selected. The main components of screw jacks are gear housing, trapezoidal lifting screw, worm screw and worm gear. Worm screw is rotated manually or by motor, then the worm gear will be rotated by the worm screw and the lifting screw moves through the rotating worm gear. The linear motion speed of lifting screw depends on thread size and rotation ratio of worm gears.

This is the standard version. For the installation, you will need the same amount of space below the screw jack gearbox as you need above.

Translating Screw Jacks

Worm Gear Translating Screw Jacks

Bevel Gear Translating Screw Jacks

Rotating Screw Jacks (traveling Nut)

Traveling Nut screw Jacks are another option. This type of jack is ideal for applications that cannot accommodate a screw protection tube or require a flush mount. The lifting screw does not move up and down. It only rotates around its axis. The traveling nut moves along the screw. The lifting nut of the screw jack is made of bronze to decrease friction.

Space on only one side of the jack is required for the installation.

Rotating Screw Jacks

Traveling Nut Worm Gear Screw Jacks

Traveling Nut Bevel Gear Screw Jacks

Keyed Screw Jacks(Anti-rotation)

Keyed screw jacks all called anti-rotation screw jack. In applications where rotation cannot be prevented externally, a keyed design screw jack is required. This design is only available for translating screw jacks. For keyed screw jack, there is two versions locked against rotation on the tube or on keys.

Screw Jack Use Precautions

1. Choose the screw jack lift regardless of static load, dynamic load, and impact load shall not exceed the maximum load allowed to bear, according to the safety factor, the use of stroke, proofreading screw stability selection with full capacity of the screw jack lift.

2. Be sure to pay attention to the screw shaft speed and bear the load collocation for the screw jack lift to allow the maximum load, allow additional load, allow the speed of the screw shaft, and other items to check if the product data will cause significant damage to the screw jack lift equipment.

3. When the screw jack lift is working, the surface temperature of the deceleration part should be controlled within the range of -15 C ~ 80 C to ensure that the surface temperature of the movable nut is also within the above range.

4. The allowable speed of the input shaft is 1500r/min. The input shaft cannot exceed this speed.

5. for the same axis to connect several lifts, please check the strength of the input shaft so that each lift bear torque should be within its allowable input shaft torque.

6. The starting torque of the driving source should be more than 200% of the operating torque.

7. When working at zero degrees Celsius, the machine's efficiency decreases due to the influence of the change of lubricating oil viscosity, so there must be an excellent driving source.

8. JWM series screw jack lift theoretically has a self-locking function. Still, it will cause self-locking function failure in significant vibration and impact occasions, so it is necessary to add a braking device or choose a driving source with braking.

9. JWB series screw jack lift itself does not have a self-locking function; to prevent the reversal due to axial load and the weight of the lead screw, it is necessary to add a braking device or choose a driving source with braking; please ensure that the braking torque is greater than the holding torque.

10. The operating environment of the lift is as follows:

Place of use An indoor area without rainwater intrusion
Ambient air Dust is in general factory condition
Ambient temperature -15℃ to 40℃
Relative humidity Less than 85%

11. When the screw jack lift works in a dusty place, please choose the dustproof cover expansion sleeve attachment to protect the screw. When used outdoors, please consider using a cover shell and other devices so that the machine is not directly subjected to wind and rain.

12. in the screw jack lift work, shall not enter the artificially forced shutdown. Otherwise, it will cause the elevator to receive severe damage.

13. In the case of load, please do not change the JWB series screw jack lift input shaft drive mode to manual operation; the load may cause the input shaft rotation very dangerous.

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