Machine Screw Jacks
Precision worm-gear screw jacks for industrial lifting, positioning, and levelling — from 5 kN to 350 kN capacity.
Linear Motion
Machine Screw Jacks for Precise Linear Motion
AG machine screw jacks convert rotary motion into precise linear movement through a worm gear drive mechanism. Available in capacities from 5 kN to 350 kN, these jacks are engineered for lifting, lowering, pushing, pulling, and precise positioning across a wide range of industrial applications. Each unit combines a hardened worm shaft with a bronze worm gear for maximum durability and smooth, reliable operation.
Configurations
Three Operating Configurations
Select the configuration that matches your application — translating screw, rotating screw, or keyed translating for anti-rotation requirements.
Translating Screw — Type TP
The most common configuration. The worm gear drives the screw spindle up or down in a linear path while the spindle itself does not rotate. Ideal for lifting platforms, press tables, and positioning applications where the load connects directly to the moving screw end.
- Motion TypeLinear (screw translates, does not rotate)
- Anti-RotationProvided by internal keyway
- Load ConnectionClevis, flange, or threaded end
- Best ForPlatforms, press tables, dam gates, stage lifts
Rotating Screw — Type TPR
In this configuration, the screw spindle rotates while the nut travels linearly along the screw. The load is attached to the travelling nut. This is suited for applications requiring a compact installation height, or where the screw needs to be supported at both ends for long strokes.
- Motion TypeScrew rotates, nut translates linearly
- Anti-RotationExternal guide required for nut
- Load ConnectionVia travelling nut with mounting flange
- Best ForLong strokes, dual-support installations, conveyor adjustment
Keyed Translating Screw
A translating screw with an additional external keyway machined along the screw spindle. The key engages with a mating slot in the housing cover, positively preventing screw rotation. This configuration is required when high torsional loads or external forces could otherwise cause uncontrolled screw rotation.
- Motion TypeLinear (positive anti-rotation via keyway)
- Anti-RotationExternal keyway on screw + key slot in cover
- Load ConnectionClevis, flange, or threaded end
- Best ForHigh torsion loads, solar trackers, precision tooling
Technical Data
Specifications by Model
10 models from AG-SJ-05 to AG-SJ-350 cover the full range of industrial lifting requirements. Two gear ratios per model for optimised speed vs. load performance.
| Model | Capacity (kN) | Screw Dia. (mm) | Gear Ratio | Travel/Rev (mm) | Max Input Speed (rpm) | Efficiency (%) | Weight (kg) |
|---|---|---|---|---|---|---|---|
| AG-SJ-05 | 5 | 20 | 1/4 | 5 | 1800 | 35 | 3.5 |
| AG-SJ-05 | 5 | 20 | 1/8 | 2.5 | 1800 | 28 | 3.5 |
| AG-SJ-10 | 10 | 24 | 1/4 | 6 | 1800 | 35 | 5.2 |
| AG-SJ-10 | 10 | 24 | 1/8 | 3 | 1800 | 28 | 5.2 |
| AG-SJ-25 | 25 | 30 | 1/4 | 6 | 1800 | 33 | 8.4 |
| AG-SJ-25 | 25 | 30 | 1/8 | 3 | 1800 | 26 | 8.4 |
| AG-SJ-50 | 50 | 36 | 1/8 | 4 | 1500 | 30 | 14.6 |
| AG-SJ-50 | 50 | 36 | 1/16 | 2 | 1500 | 22 | 14.6 |
| AG-SJ-100 | 100 | 46 | 1/8 | 6 | 1200 | 28 | 28.5 |
| AG-SJ-100 | 100 | 46 | 1/16 | 3 | 1200 | 22 | 28.5 |
| AG-SJ-150 | 150 | 55 | 1/8 | 6 | 1000 | 27 | 42.0 |
| AG-SJ-150 | 150 | 55 | 1/16 | 3 | 1000 | 21 | 42.0 |
| AG-SJ-200 | 200 | 65 | 1/16 | 4 | 900 | 25 | 62.0 |
| AG-SJ-200 | 200 | 65 | 1/24 | 2.7 | 900 | 20 | 62.0 |
| AG-SJ-250 | 250 | 70 | 1/16 | 4 | 800 | 24 | 78.0 |
| AG-SJ-250 | 250 | 70 | 1/24 | 2.7 | 800 | 19 | 78.0 |
| AG-SJ-300 | 300 | 80 | 1/16 | 5 | 700 | 23 | 98.0 |
| AG-SJ-300 | 300 | 80 | 1/24 | 3.3 | 700 | 18 | 98.0 |
| AG-SJ-350 | 350 | 85 | 1/16 | 5 | 600 | 22 | 118.0 |
| AG-SJ-350 | 350 | 85 | 1/24 | 3.3 | 600 | 17 | 118.0 |
Specifications are for trapezoidal screw versions. Ball screw variants offer higher efficiency (up to 90%) and faster travel speeds. Contact us for ball screw specifications.
Screw Technology
Trapezoidal vs. Ball Screw
Choose the screw type based on your duty cycle, speed, and self-locking requirements.
| Parameter | Trapezoidal Screw | Ball Screw |
|---|---|---|
| Efficiency | 25–35% | 80–90% |
| Self-Locking | Yes — holds load without brake | No — external brake required |
| Positioning Accuracy | ±0.1 mm | ±0.02 mm |
| Max Linear Speed | Moderate (limited by friction heat) | High (lower friction, higher speeds) |
| Duty Cycle | Up to 30% ED | Up to 100% ED |
| Noise Level | Low | Very Low |
| Maintenance | Periodic lubrication | Sealed, longer intervals |
| Cost | Lower | Higher (precision ground) |
| Typical Use | Static holding, infrequent positioning | Continuous motion, high-speed cycling |
Mounting Options
Mounting Configurations
Standard mounting forms for flexible integration into your machine design.
Form S — Base Mounted
Standard foot-mounted configuration. The jack housing is bolted to the base structure via machined mounting feet. The screw extends vertically upward. Most common mounting for lifting platforms, press tables, and general positioning.
Form B — Top Plate Mounted
Inverted mounting with the housing bolted to an overhead structure. The screw extends downward. Used when the jack needs to push down or when the housing must be mounted to an upper frame, gantry, or ceiling structure.
Form D — Flange Mounted
The housing is attached via a machined flange for direct coupling to machine frames or other mechanical assemblies. Provides precise axial alignment and is used when space constraints prevent foot mounting. Available in horizontal and vertical orientations.
Synchronized Systems
Multi-Jack Lifting Systems
Synchronize two, three, four, or more screw jacks with a single motor drive for perfectly level lifting and positioning.
How It Works
Multiple screw jacks are mechanically linked via bevel gearboxes and cardan shafts (connecting shafts), all driven by a single electric motor through a common worm shaft. Because every jack is mechanically coupled, all lifting points move at precisely the same speed — ensuring perfect synchronization without the need for electronic controls or feedback sensors.
Bevel Gearboxes
Right-angle power distribution — redirect the drive shaft around corners and to multiple jack positions. Available in T-type (1 input, 2 outputs) and L-type (1 input, 1 output at 90°).
Cardan Shafts
Telescopic connecting shafts with universal joints transmit torque between jacks and gearboxes. Available in standard lengths from 500 mm to 6000 mm, with custom lengths on request.
System Layouts
Standard 2-point, 3-point, 4-point, and 6-point configurations. Custom layouts for complex geometries — we design the complete drive train including motor, gearboxes, shafts, and jacks.
Applications
Where Screw Jacks Work
From heavy steel mills to precision stage machinery — screw jacks deliver reliable linear motion in the most demanding environments.
Steel & Metal Processing
Rolling mill adjustment, furnace door positioning, ladle tilting mechanisms, and continuous casting mould oscillation. High-capacity AG-SJ-200 to AG-SJ-350 models for heavy loads.
Automotive Manufacturing
Body-in-white welding fixtures, press die height adjustment, paint booth conveyor levelling, and assembly line platform positioning with synchronized 4-point systems.
Solar Tracking Systems
Single-axis and dual-axis solar panel trackers. Keyed translating screw configuration prevents wind-induced rotation. Ball screw variants for continuous daily tracking cycles.
Stage & Theatre Machinery
Precision stage lifts, orchestra pit platforms, scenery fly systems, and revolving stage mechanisms. Low-noise trapezoidal screws with synchronized multi-point lifting for perfectly level stage movement.
Press Tables & Die Setting
Adjustable-height press bolsters, die clamping systems, and platen levelling. Self-locking trapezoidal screws hold the set position without hydraulic pressure or external braking.
Dam Gates & Water Management
Sluice gate positioning, weir adjustment, and floodgate operation. Heavy-duty AG-SJ-250 to AG-SJ-350 models with corrosion-resistant coatings for wet and submerged environments.
Product Families
Screw Jack Series
Three distinct product families to match your application requirements — from self-locking static loads to high-speed precision positioning.
Standard Trapezoidal Series
Self-locking mechanical screw jacks with trapezoidal thread — the most versatile choice for lifting, pushing, pulling, and aligning loads. Holds position without a brake when power is off.
Ball Screw Series
High-efficiency ball screw jacks for intensive duty cycles and precision positioning. Recirculating ball nut delivers up to 90% efficiency with minimal friction and heat generation.
Heavy Duty Series
Engineered for extreme loads and demanding environments. Reinforced cast iron housings, hardened worm gears, and oversized screw spindles for steel mills, presses, and heavy infrastructure.
Accessories
Accessories & Options
Extend the capability and lifespan of your screw jack system with purpose-built accessories for protection, control, safety, and lubrication.
Protective Bellows
Elastic accordion-style bellows shield the screw spindle from dust, debris, metal chips, and moisture. Essential for foundry, mining, and outdoor installations. Available in neoprene, silicone, and heat-resistant materials.
Limit Switches
Mechanical and electronic stroke-limiting devices prevent over-travel at both ends of the screw stroke. Configurable setpoints with adjustable cams. Available with NO/NC contacts and proximity sensor options.
Motor Flanges & Couplings
IEC standard motor flanges (B5/B14) for direct motor mounting. Flexible jaw couplings and rigid couplings for connecting motors, gearboxes, and transmission shafts. Accommodates frame sizes 56 to 180.
Safety Nuts
Dual-nut safety system for wear monitoring and fail-safe operation. The primary nut carries the load while the secondary nut monitors wear — when the gap closes, it signals that the primary nut needs replacement before failure.
Anti-Rotation Guides
External linear guide systems that positively prevent screw rotation in translating configurations. Dual-guide rail design absorbs side loads and torsional forces. Required for applications with external lateral forces on the screw.
Oil Bath Lubrication Systems
Sealed oil bath lubrication for continuous-duty and high-cycle applications. The screw operates within a sealed oil chamber that provides consistent lubrication and heat dissipation. Extends service life and reduces maintenance intervals.
Special Variants
Special Configurations
Purpose-built screw jack variants for harsh environments, hygienic applications, and unique engineering challenges.
Corrosion Resistant
Stainless steel construction (AISI 316) and Niploy coating treatment for marine, chemical processing, and outdoor environments. Resists saltwater, acids, and industrial chemicals while maintaining full mechanical performance.
High Temperature
Viton seals, high-temperature lubricants, and heat-treated materials for operation in foundries, furnace environments, and steel processing applications where ambient temperatures exceed standard ratings.
Food & Pharmaceutical Grade
Stainless steel construction with food-grade Niploy coating and NSF-approved lubricants. Designed for washdown environments with strict hygiene regulations in food processing, dairy, beverage, and pharmaceutical production lines.
Custom Engineering
Application-specific screw jack designs built to your exact requirements. Custom stroke lengths, special gear ratios, non-standard mounting forms, and integrated motor packages. 30+ years of custom engineering experience.
Power Transmission
Bevel Gearboxes for Multi-Jack Systems
90° power redirection using spiral bevel gears — the critical link in synchronized multi-jack lifting and positioning systems.
Gleason Spiral Bevel Technology
Our bevel gearboxes use Gleason-type spiral bevel gears for quiet, efficient 90° power transmission. The spiral tooth profile provides gradual engagement, reducing noise and vibration while handling higher torque loads than straight-cut bevel gears. Available in 9 standard sizes to match every screw jack in our range.
- Gear TypeGleason spiral bevel gears
- ConfigurationsL-type (1:1), T-type (1:2), cross (1:3)
- Ratios1:1, 1:2, 1:3 (up to 1:12 available)
- Sizes10 sizes matching AG-SJ-05 to AG-SJ-350
- HousingCast iron (stainless steel on request)
- Drive OptionsElectric, hydraulic, pneumatic, manual
Synchronized System Configurations
Motor → L-type bevel → 2 jacks. Simple linear lifting with one motor and one gearbox. Ideal for platform tilt adjustment and press table levelling.
Motor → T-type bevel → 3 jacks via connecting shafts. Triangular lifting for three-legged platforms, antenna positioners, and stage lifts.
Motor → cross bevel → 4 jacks with intermediate shafts. Rectangular platform lifting, mould adjustment in presses, and large-format solar tracking arrays.
Industry Solutions
Application Showcase
From solar farms to opera houses — screw jacks deliver reliable linear motion across every major industry.
Solar Panel Tracking
Single-axis and dual-axis solar trackers using keyed translating screw jacks to tilt photovoltaic panels throughout the day. Ball screw variants handle continuous daily cycling with minimal maintenance. Multi-jack synchronized systems for large-format solar arrays.
Stage & Theatre Platforms
Precision stage lifts, orchestra pit elevators, and scenery positioning systems — used in world-class venues including opera houses and concert halls. Self-locking trapezoidal screws eliminate the risk of platform drop during power failure. Ultra-quiet operation essential for live performances.
Press Machines
Adjustable press bolsters, die height adjustment, and platen levelling for hydraulic and mechanical presses. Self-locking trapezoidal screws hold the set position permanently without hydraulic pressure — reducing energy consumption and eliminating drift.
Steel Mill Equipment
Rolling mill roll gap adjustment, continuous casting mould oscillation, ladle tilting, and furnace door positioning. Heavy-duty AG-SJ-300 to AG-SJ-350 models with high-temperature seals and heat-resistant bellows for operation near molten metal zones.
Packaging Lines
Format changeover systems, conveyor height adjustment, and sealing bar positioning in food and pharmaceutical packaging machinery. Food-grade stainless steel variants with NSF H1 lubricants for direct contact with packaging materials.
Platform Lifting & Levelling
Helicopter landing platforms, vehicle inspection ramps, loading dock levellers, and industrial work platforms. Synchronized 4-point and 6-point systems ensure perfectly level lifting across large platform areas with a single motor drive.
Antenna Positioning
Large satellite dish and radar antenna azimuth/elevation drives. Ball screw jacks provide smooth, precise angular positioning for telecommunications, defense radar, and radio telescope applications. Weather-sealed housings for outdoor installation.
Shipbuilding & Marine
Ship hull positioning during construction, drydock levelling systems, and marine hatch opening mechanisms. Corrosion-resistant stainless steel versions with Niploy coating for saltwater environments. Heavy-duty models for hull block positioning up to 350 kN.
Budgetary offer — Screw Jacks
Tell us the duty and we’ll send you a number
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Prefer to talk? +91 98203 83719 or +91 98205 18093.
Engineering Note: Euler Buckling for Long Strokes
For screw jacks with strokes exceeding 500 mm, the free (unsupported) length of the screw spindle must be verified against Euler's critical buckling load to ensure the screw does not buckle under compressive load. The critical load depends on the screw diameter, unsupported length, end-fixity conditions, and the material's modulus of elasticity.
Where Fcr is the critical buckling force, n is the end-fixity factor (0.25 to 4.0 depending on mounting), E is modulus of elasticity, I is the screw's second moment of area, and L is the free length. A safety factor of at least 2.5 is recommended. For strokes above 500 mm, contact our engineering team for buckling verification — we will confirm whether the selected model is safe or recommend an alternative (larger screw diameter, guided column, or rotating screw configuration with dual end supports).