Prestressing Pile Foundation Rebar Clamps

Heavy-Duty PC Steel Bar Clamping Jaws for Automated Button Heading Machines

The Challenge

Hydraulic button heading of high-tensile PC bars causes extreme axial shock and crushing loads. Generic clamping blocks suffer stress cracking, cavity deformation, or gripping loss under 50 to 200 kN pressure, allowing 1420 MPa bars to slide and causing incomplete button formation or structural eccentricity.

Our Solution

ALAS manufactures heavy-duty heading machine clamping jaws forged from premium tool steels (AISI H13 / AISI D2). Processed via multi-stage vacuum heat treatment and localized induction hardening along the contact pockets, our clamps maintain stable gripping geometries on high-frequency heading carousels.

Applications: SBPDL-series prestressing steel bars (1275–1420 MPa grade).

Bar Range: Drop-in fit for Φ7.1 mm, Φ9.0 mm, Φ10.7 mm, and Φ12.6 mm diameters.

Key Metric: Core coaxiality alignment error limited strictly to within 0.05 mm.

Engineering Dynamics & Technical Advantages

Precision Coaxiality Control: Precision CNC wire-cut and ground V-groove profiles restrict alignment deviation to under 0.03 mm. This eliminates material shortage during the plastic upsetting phase and forces the button head to expand concentrically with the bar axis.

Surface Scarring Mitigation: The internal clamping interface contour features calibrated friction teeth that are stress-balanced to grip the induction-hardened PC steel bar uniformly. This locks the steel bar without deep scoring, notch indentation, or localized micro-fracturing that damages the bar's tensile properties.

Rigid Anti-Deformation Matrix: The balanced core hardness and toughness of H13 / D2 steel absorb repetitive hydraulic strokes, preventing the clamping blocks from expanding laterally and ensuring standardized button-head diameters (1.5–2.0 × the bar diameter).

Technical Specification Matrix

Standard Tooling Dimensions & Custom Capabilities

To ensure a precise drop-in fit with your existing automated wire blanking carousels and shearing actuators, our manufacturing window covers the following precision specifications:

Thickness Profile: Machined strictly within ±0.01 mm to maintain stable rigid seating alignment.

Machining Interfacing: Supports custom countersunk bolt holes, threaded counterbores, and high-precision sliding location slots.

All custom cutter blocks are manufactured strictly to client blueprints or original equipment manufacturer (OEM) part numbers.

Matched Processing Line Consumables & Compatibility

ALAS supplies complete replacement components and offers 100% geometric interchangeability for global automated spun pile and concrete pole equipment, including brands like NCB (Japan), Taichang (South Korea), Haicheng & Haiyu (China), and mainstream carousels like Kajimoto and Skako Concrete. Cross-reference support is available by supplying machine models or blueprints.

Packaging & Anti-Rust

Treated with heavy-duty synthetic anti-rust oil, wrapped in VCI paper, vacuum-sealed in barrier bags, and shipped in ISPM-15 compliant export wooden crates with desiccant packs.

Technical FAQ & Preservation Standards

Q1: How to prevent eccentric heading?

Keep mounting slots clean with compressed air. ALAS jaws maintain alignment tolerances under 0.03 mm.

Q2: How to fix clamp slippage on Φ12.6 mm bars?

ALAS uses forged H13/D2 tool steel with induction-hardened pockets (50–60 HRC) to securely lock high-pressure bars without slipping or deep scuffing.