How to Select Industrial Screw Jacks and Bevel Gearboxes for Your Application

To select an industrial screw jack or bevel gearbox, start with the motion your machine must produce, then size the components around the real operating conditions. For a screw jack, define the load, stroke, travel speed, mounting arrangement, duty cycle, and whether the load must be held when motion stops. For a bevel gearbox, define input speed, output speed or ratio, required torque, shaft directions, operating hours, and environment. We recommend confirming the calculations and allowable operating limits with the supplier before specifying or ordering equipment.

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The two products can be used separately or together: a bevel gearbox changes the direction and ratio of rotary drive, while a screw jack converts rotary input into linear movement. A suitable selection depends on the complete drive system rather than on a single headline rating. The steps below help you prepare a clear specification and avoid common sizing errors.

Start with the Application Goal

Describe what the machinery needs to do before choosing a product model. State whether you need to lift, lower, position, tilt, or synchronize a load, and identify how many axes must move. Include what happens during starting, stopping, and an emergency stop, since these conditions can affect load support, braking, and component selection.

Separate known requirements from assumptions. For example, a stated payload may not include the weight of a platform, fixture, or connected tooling. If the load varies, provide both the normal and maximum expected values, and explain whether the load is centered or offset.

Step-by-Step Selection Process

1. Define the Screw Jack Load and Motion

For each jack, establish the axial load it will carry, the required travel distance, and the desired linear speed. Determine whether the jack will push, pull, or operate in both directions, and whether one jack or multiple jacks will support the structure. Where several jacks work together, specify the synchronization method and how uneven load sharing will be prevented or managed.

Use the worst credible operating load for preliminary sizing, not just the average production load. Account for moving structure weight, process forces, acceleration, and any load offset that may introduce side force. A screw jack is generally intended to transmit axial force; arrange guides or structure supports to manage lateral forces unless the supplier confirms the configuration can accommodate them.

2. Check Stroke, Speed, and Duty Cycle

Specify the full stroke and the number of movements expected in a typical operating period. Duty cycle is important because frequent or continuous movement can create different thermal and wear demands from occasional adjustment. Provide the expected operating hours, cycles per hour, and rest periods where available.

As a purely illustrative sizing brief—not a product rating—a machine might require a 12 kN lifting load, a 250 mm stroke, and a 20 mm/s travel speed. These values show the type of information a supplier needs; they do not establish that a particular jack can meet the duty, stability, or safety requirements. The selected model must be checked against its manufacturer’s load, speed, stroke, and operating-condition data.

3. Evaluate Stability and Load Holding

For a screw jack with an extended screw, ask the supplier to assess buckling risk at the maximum extension. The result depends on factors such as screw dimensions, unsupported length, end conditions, and loading, so nominal load capacity alone is not enough. Also check whether the installation introduces bending, vibration, or impact.

Do not assume that every screw jack is self-locking under every condition. Back-driving behavior can depend on the screw design, load, lubrication, wear, and vibration. If the load must remain in position after power loss, specify the holding requirement and ask whether a brake, mechanical lock, or other independent safety measure is needed.

4. Size the Bevel Gearbox and Drive

For a bevel gearbox, define the motor or input speed, the required output speed, and the torque needed at the gearbox output. The ratio relates input speed to output speed, but torque selection also depends on the drive, operating pattern, and gearbox efficiency. Confirm the required service conditions with the supplier rather than selecting a unit from ratio alone.

Provide the shaft arrangement, rotation direction, mounting position, and connection details. Identify whether the gearbox drives a screw jack directly, through a shaft, or as part of a multi-jack system. If several outlets or right-angle changes are involved, share a layout drawing so the supplier can check alignment, shaft access, and installation space.

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5. Specify the Environment and Interfaces

Describe ambient temperature, dust, moisture, washdown, corrosive exposure, and any nearby heat sources. These details may influence housing, seals, lubrication, surface treatment, and protection requirements. State the available space and the way the unit attaches to the machine, including flange, base, shaft, and coupling dimensions.

When the machine operates outdoors or in a demanding process area, avoid relying on a general description such as “industrial environment.” Give the supplier the actual exposure and cleaning conditions. Ask which environmental limits and maintenance requirements apply to the proposed configuration.

Key Decisions Before You Request a Quote

Choose the Right Screw Jack Configuration

Common screw jack configurations differ in how the screw moves and how the load connects. A translating screw moves linearly through the jack, while a rotating screw requires the connected load or nut arrangement to translate. The correct configuration depends on available space, guidance, stroke, and how the machine connects to the moving member.

Also specify whether the application needs a single jack or a coordinated system. Multiple jacks may require a common drive shaft, bevel gearboxes, or another synchronization arrangement. The design should address mechanical alignment and the possibility of unequal loads, not only the nominal total capacity.

Match Gearbox Ratio, Torque, and Mounting

Choose a bevel gearbox ratio that supports the required output speed while allowing the drive to provide the necessary torque. Check the motor, coupling, shafts, and driven equipment as one system. Confirm whether the specified torque is continuous, intermittent, or associated with starting and stopping.

Mounting orientation and lubrication requirements should be confirmed for the actual installation. If the gearbox will be installed in a non-standard position, state this before purchase, because the permitted orientation may depend on the design and lubrication method. Request written confirmation of operating limits for the selected configuration.

Common Selection Mistakes

• Sizing from payload alone: Omitting fixtures, platform weight, process forces, or load distribution can lead to an incomplete specification.
• Ignoring maximum extension: A jack may face different stability conditions at full stroke than at a shorter extension.
• Choosing a gearbox by ratio only: Ratio does not confirm torque capacity, operating suitability, or compatibility with the drive.
• Assuming load holding: Confirm back-driving and power-loss behavior instead of treating self-locking as guaranteed.
• Leaving out the environment: Temperature, moisture, dust, and cleaning can affect the requested configuration and maintenance plan.
• Not checking interfaces: Verify shaft dimensions, mounting points, alignment, and connection details before finalizing the design.

Improve the Selection and Buying Process

Prepare a concise application brief containing a machine sketch or layout, load cases, required motion, duty cycle, environmental conditions, and interface dimensions. Clearly label estimates and identify any requirements that are safety-critical. This gives the supplier a basis to identify missing information before a quotation becomes a purchase specification.

Ask for the proposed model, configuration, ratio, relevant operating limits, mounting details, and maintenance guidance in writing. Where the system includes several jacks or gearboxes, request confirmation of the complete arrangement rather than reviewing each component in isolation. If the machine has unusual loads, frequent cycling, or limited space, share those constraints early.

How WGT Can Support Your Specification

At WGT, we can review your application information for industrial screw jacks and bevel gearboxes and help identify the product details that need confirmation. Share the load, stroke, speed, duty cycle, input and output requirements, mounting arrangement, environment, and available drawings. If some values are not yet known, indicate that clearly so they can be treated as open design points rather than assumed facts.

For a practical inquiry, include the required quantity, preferred delivery schedule, and any customization or documentation needs. Our team can then discuss a suitable configuration and clarify which technical details must be approved before ordering. Final selection should be based on the confirmed application data and the operating limits of the proposed equipment.

Summary and Next Steps

• Define the complete load and motion requirements before selecting a screw jack.
• Check stroke, speed, duty cycle, stability at extension, and load-holding needs.
• Select a bevel gearbox using speed, torque, ratio, shaft arrangement, and mounting information together.
• Account for environment, interfaces, synchronization, and the behavior of the full drive system.
• Send WGT an application brief and drawings to discuss a configuration for your machinery.

The direct answer is to select industrial screw jacks and bevel gearboxes as parts of one engineered motion system: first define the load and movement, then confirm capacity, stability, drive requirements, mounting, and environment. Your next step is to compile the application data and ask a qualified supplier to review the proposed configuration before placing an order.