Scaffolding Adjustable Hollow Screw Base Jack

1.Product Description

2.Product Advantage
A. High quality materials, higher quality.
    Material--The product material is Q235 or Q345 carbon steel which is higher than the standard as the raw material.
    Quality assurance, not easy to crush deformation.

B. Advanced technology, better performance
    Products using advanced technology, avoid the production malpractice of old craft, causes the product the anti-deformation and the anti-stretching performance to be stronger, more fits the scaffolding.

C. Anti-rust treatment, longer service life.
   After passivation and surface galvanized anti-rust treatment, it is corrosion resistance is better than the ordinary tubes, longer service life.

D. Standard production, more secure.
    According to the professional design and advanced technology, all products are manufactured in strict accordance with EN74 and BS1139 standards, quality guarantee, ensure construction safety and personnel safety.

3.Base Jack FAQs

Q:How to check if a base jack is qualified?

A:Weld inspection: The weld between the base plate and the screw must be fully penetrated, without porosity or cracks.
    Thread inspection: The nut should be able to rotate and tighten smoothly on the screw without jamming.
    Material certification: A material certificate (Mill Certificate) conforming to standards and a load-bearing capacity test report (SGS) are required.

Q:How to Choose Between Solid Base Jacks and Hollow Base Jacks?

A:The choice of base jack primarily depends on project load requirements and cost control. It is recommended to match the base jack to the design value of the axial force of a single upright based on engineering calculations, ensuring a safety factor of no less than 2:1.
    Solid Base Jacks: Offer extremely high load-bearing capacity and are typically used in heavy-duty support systems (such as for cast-in-place bridge beam construction). They are heavy and highly stable.
    Hollow Base Jacks: Made from seamless steel tubing, they are lighter and easier for workers to handle. They are suitable for standard building formwork system and offer good cost-effectiveness.

Q:What is the difference between U-Head Jack and Base Jack?

A:Although both use screws to adjust height, their functional logic is completely different:
    Base Jack: Typically used for bottom support, with a flat steel base, focusing on pressure resistance and preventing settlement.
    U-Head Jack: Typically used for top support, equipped with a U-shaped open steel plate, focusing on creating crossbeams and preventing tipping.

Q: What are the main functions and structure of a base jack in building construction?

A: A base jack (adjustable base jack) is a core component of scaffolding and formwork support systems. Its main structure consists of solid or hollow threaded rods, cast iron adjusting nuts, and a reinforced base plate. Its core function is to compensate for uneven ground conditions by adjusting the height of the nuts, ensuring that the vertical uprights of the scaffolding are on a horizontal baseline, thereby achieving overall load balance of the support system.

Q: How does the surface treatment of an adjustable base jack (galvanized vs. painted) affect its lifespan?

A: Surface treatment directly determines the lifespan and corrosion resistance of the base jack:
    Hot-dip galvanized: Offers the strongest corrosion resistance, with a zinc layer thickness of 60-80μm. Suitable for outdoor projects in high salt spray and high humidity environments, with a lifespan of over 10 years.
    Electro-galvanized: Provides a smooth and aesthetically pleasing surface at a lower cost, suitable for general environments.
    Painted: Lowest cost, but the coating is prone to peeling during construction and handling. Short-term use in dry environments is recommended.

Q: How to calculate the load-bearing capacity of a base jack?

A: The load-bearing capacity depends on the diameter and material of the screw (e.g., Q235 or Q345 steel). The slenderness ratio must be considered in the calculation.
    Note: The higher the adjustment height, the weaker its stress stability.

Q: Why do Base Jack screws typically use a "cold rolling" process?

A: Higher strength: Cold rolling causes work hardening in the metal, increasing the tensile strength of the thread. 
    Smoother surface: Compared to machining, rolled threads have a smoother surface, resulting in less resistance when adjusting the nut. 
    Higher material utilization: Chip-free machining better meets modern green manufacturing standards.