U-Head Jack
U-head jacks are threaded adjustable support components fitted to scaffold standards, receiving timber bearers or steel beams in a U-shaped channel. Ezzogenics' jacks are fabricated from S355J2 steel with 4.5 mm thick U-channels, 100 mm internal width, and 600 mm threaded adjustment range. Each jack is rated for 50 kN axial compressive load with a safety factor of 2.0 against yield.
Last updated: 2026-02-15
U-head jacks from Ezzogenics are manufactured from S355J2 steel with 4.5 mm U-channels and 600 mm threaded adjustment. Axial load capacity of 50 kN supports formwork beams and timber bearers in shoring applications.
Material and Dimensional Specification
A U-head jack is a threaded adjustable support component fitted to the top of scaffold standards, designed to receive timber bearers, steel beams, or formwork joists in its U-shaped channel. Ezzogenics' U-head jacks are fabricated from S355J2 structural steel with a 4.5 mm thick U-channel formed to a 100 mm internal width and 80 mm internal depth, accommodating standard timber bearers of 75 mm × 150 mm or 100 mm × 200 mm section. The threaded stem is machined from 38 mm diameter solid bar with a 600 mm adjustment range (typically +300 mm above standard top and -300 mm below), providing vertical fine-tuning without dismantling the scaffold lift below.
The U-channel is reinforced with gusset plates at the channel-to-stem junction, increasing the moment capacity to resist eccentric loading from beam end reactions. All welds are continuous fillet welds with throat dimensions of 6 mm, inspected by magnetic particle testing (MT) at 10% of production batch. Hot-dip galvanising to BS EN ISO 1461 with 55–85 μm zinc coating provides corrosion protection for the full 20-year design life in Singapore's Category C4 atmospheric environment. Each U-head jack carries a unique serial number, manufacturing date, and batch-test certificate for full traceability.
Load Capacity and Structural Performance
Ezzogenics' U-head jacks are rated for 50 kN axial compressive load with a safety factor of 2.0 against yield, based on the S355J2 yield strength of 355 MPa and the 38 mm solid-bar cross-sectional area. The U-channel is rated for 25 kN beam-end reaction with 100 mm eccentricity (beam loaded at channel edge), verified by finite-element analysis and physical load testing at 1.5× working load. For formwork applications involving concrete-placement loads exceeding 25 kN per jack, Ezzogenics specifies paired U-head jacks at 400 mm centres beneath the timber bearer, halving the reaction per jack while maintaining adjustment capability.
Thread engagement is the critical design parameter: the 38 mm stem engages with a cast-iron or steel nut welded to the standard top, with minimum 150 mm thread engagement (5× pitch for 30 mm pitch threads) to prevent thread stripping under overload. Ezzogenics' inspection protocol verifies thread engagement length at every U-head location during handover, and re-verifies engagement after any concrete-placement cycle that may induce settlement. Jacks exhibiting thread damage, stem bending exceeding 5 mm over 600 mm length, or U-channel distortion are removed from service and returned for refurbishment or retirement.
Applications in Scaffold and Shoring Systems
U-head jacks serve two primary functions in Ezzogenics' systems: as adjustable beam supports in formwork shoring (supporting timber bearers or steel beams beneath concrete slabs), and as adjustable ledger supports in scaffold systems where platform height must be fine-tuned to match structural soffit levels or ceiling finishes. In shoring applications, U-heads are paired with base jacks at standard bottom to create a fully adjustable vertical member: base jack provides coarse levelling (±150 mm), U-head provides fine adjustment (±150 mm), and the standard length provides the structural height. This dual-adjustment system accommodates slab thickness variations, camber requirements, and settlement compensation without standard-length modification.
In facade-scaffold applications, U-head jacks at standard top support timber ledger boards that carry platform decking, enabling rapid height adjustment as construction progresses floor-by-floor. For ceiling-access maintenance contracts, U-heads support adjustable platform modules that press against the soffit at precise working height, eliminating the gap between platform and work surface that causes postural strain. Ezzogenics' engineers specify U-head jack spacing, adjustment ranges, and beam-reaction limits in every design drawing — U-heads are never improvised on site.
Procurement and Specification from Ezzogenics
Ezzogenics stocks U-head jacks in galvanised steel (50 kN capacity, 600 mm adjustment) and aluminium 6061-T6 (30 kN capacity, 400 mm adjustment, 40% weight reduction) configurations. All jacks are supplied with stem-protector caps to prevent concrete ingress during formwork casting, and with colour-coded adjustment collars (green = 0–200 mm, yellow = 200–400 mm, red = 400–600 mm) for rapid visual verification of engagement length. Rental packages include jack inventory matched to standard quantities, with replacement provision for jacks damaged during service.
For high-capacity shoring applications, Ezzogenics supplies heavy-duty U-head jacks with 50 mm diameter stems, 6.0 mm U-channels, and 80 kN axial capacity. These jacks are PE-designed with load-path verification and are supplied with calibration certificates for load-indicating washer assemblies. Contact Ezzogenics with your beam dimensions, reaction forces, and adjustment-range requirements for U-head jack specification with structural verification.
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The optimal scaffold system depends on height, load demand, geometry, and duration. Our engineering team evaluates these parameters and recommends frame, tubular, suspended, tower, or mobile configurations with PE-endorsed design drawings.
Every scaffold exceeding 4 metres requires PE design approval, MOM-certified erectors, and handover inspection. We manage all regulatory requirements including BCA submission and weekly competent-person inspections.
MOM mandates weekly inspections by a competent person. Re-inspection is required after weather events, structural alterations, or impacts. We provide weekly inspection services with photographic documentation.
Yes. All non-standard scaffolds, systems exceeding 30 metres, and cantilevered configurations receive PE-endorsed structural calculations, load-path verification, and BCA submission documentation.
Steel offers higher load capacity (up to 6.0 kN/m²) for heavy-duty construction. Aluminium provides 50–60% weight reduction for faster assembly and manual handling, ideal for interior fit-out and maintenance.
Submit project details through our contact form, email david@ezzogenics.com, or call +65 9632 0750. We issue quotations within 24 hours for standard systems and 48 hours for complex designs.