Steel Screw Jack Manufacturer

Steel screw jack is an independent steel structural component used in building temporary support and formwork shoring works, composed of threaded steel rod, adjusting nut, base plate or U‑shaped support head. Each part undertakes separate mechanical functions, and the component can complete height adjustment and load‑bearing work as an individual unit without depending on other matching accessories. The main raw material is structural carbon steel. The threaded rod can adopt solid round steel or hollow seamless steel pipe. Solid steel rod possesses better compression and bending resistance, which is suitable for heavy‑load support conditions. Hollow steel rod reduces overall self‑weight while maintaining basic mechanical performance, applying to conventional medium‑load construction scenes. Threads are mostly processed by cold rolling, which improves surface hardness of thread teeth and reduces abrasion caused by frequent rotation during repeated use. Adjusting nuts are produced through forging or casting processes, and structural integrity of nuts directly affects locking reliability under sustained vertical load. The base plate is welded onto the bottom of steel rod. The enlarged flat plate expands contact area with bearing surface, disperses concentrated vertical pressure and lowers the risk of sinking on soft ground. The U‑shaped head provides clamping space for horizontal steel tubes or wood beams, transmitting gravity load from upper formwork and pouring materials.

Multiple surface anti‑corrosion processes are available for steel screw jack. Hot‑dip galvanizing forms dense zinc‑iron alloy covering steel rod, thread teeth and welding joints. This protective layer can resist erosion from rain, humid air and salt fog during marine transportation and long‑term outdoor exposure. Electro‑galvanizing forms relatively thin zinc coating on steel surface, fitting short‑term turnover projects with low corrosion risk. Paint surface treatment is easy to fall off under thread friction and mechanical collision, so it is seldom adopted for frequently‑circulated engineering components. According to installation position, steel screw jack can be divided into bottom base type and top U‑head type. Bottom base type is placed beneath vertical support members to bear overall vertical load and compensate height difference of foundation surface. Top U‑head type is assembled at the upper end of support uprights to fix horizontal load‑bearing members and undertake downward pressure from formwork system.

Core dimensional parameters determine actual mechanical performance of steel screw jack. Rod outer diameter is among key indicators, and larger diameter brings higher ultimate compression capacity. Effective adjustment stroke defines allowable height variation range. Excessively exposed threaded segment will reduce integral structural rigidity and increase deformation risk under load. Different sizes of base plates are selected according to ground bearing condition. Too small base plate will produce excessive ground pressure and trigger local settlement. This steel component can adapt to multiple temporary support systems, matching tube‑coupler scaffolding, ringlock shoring and other frame structures. Dimensional tolerance shall satisfy corresponding international technical standards to guarantee reliable fit during on‑site assembly.

Prior to construction application, visual inspection and sampling mechanical tests shall be carried out as independent inspection procedures. Visual check covers steel rod bending, surface cracks, welding discontinuity, thread tooth damage and anti‑corrosion layer peeling. For recycled steel screw jack, inspection standard shall be stricter. Even with intact outer appearance, accumulated metal fatigue after repeated load cycles may exist and cannot be identified merely through surface observation. Sampling compression test assesses ultimate bearing capacity and anti‑deformation property. Components with permanent bending, thread slipping and structural cracks must be sorted out and scrapped, and shall not be mixed into construction usage. Secondary processing such as cutting, welding and hole punching on finished steel screw jack is forbidden. Arbitrary modification will change original steel section property and weaken load‑bearing performance of the whole component.

Steel screw jack is designed for repeated turnover application. After dismantling of support frames, concrete mortar, dust and foreign attachments on steel rod and thread gaps need complete cleaning. Residual impurities trapped inside threads will cause nut jamming and disturb normal height adjustment and locking function in subsequent use. Finished components should be kept in dry and ventilated storage environment, sorted by type and specification, avoiding long‑term rain soaking and damp soil contact. Improper operation in construction includes over‑extending threaded rod, placing base on uneven ground and applying load exceeding rated limit. These improper usages may lead to component deformation and local stress abnormality of support frame. As an independent steel load‑bearing unit, its structural integrity and mechanical stability exert direct influence on local stress distribution of temporary shoring structures, and serve as essential condition for safe operation of construction support and formwork systems.（