Primary framing package

Scope of supply

The primary framing package is the main load-carrying steel of a pre-engineered building. It is supplied either as part of a complete PEB building kit or on its own, for example when a local contractor supplies cladding and purlins. World Steel designs, details and fabricates the package from plate in its own welding lines, and it is offered under the primary frame and steel frames product lines.

• Rigid frame columns and rafters as tapered or prismatic welded I-sections.
• Endwall columns and rafters, or full rigid endwall frames where future expansion is planned.
• Base plates, end plates, splice plates, haunches, stiffeners and cleats for purlins, girts and bracing.
• Interior columns for multi-span frames, lean-to rafters, crane brackets and canopy brackets where specified.
• High-strength bolts for all frame connections, and anchor bolts when ordered.

How the frames are made

Web and flange plates are cut on CNC plasma and oxy-fuel machines, with tapered webs nested to minimise scrap. Members are assembled and welded with automatic submerged arc welding (SAW) for the flange-to-web joints and gas-shielded FCAW or GMAW for fittings. End plates are drilled on CNC lines so that bolt patterns match between members without site rework. Quality control follows a written inspection and test plan covering dimensional checks, visual inspection of all welds and NDT of complete-penetration welds at the frequency required by the applicable code.

Options include rolled sections for small frames, hot-dip galvanizing in lieu of paint, and heavier connection details for crane or seismic frames where special detailing is required.

Materials and finishes

Standard surface preparation is abrasive blasting to ISO 8501-1 Sa 2½ followed by a shop primer or a full paint system selected to the ISO 12944 corrosivity category of the site. Hot-dip galvanizing to ASTM A123, AS/NZS 4680 or EN ISO 1461 is available for aggressive environments. See paint and coating systems.

Compliance by market

Corrosion protection options

The finish of the primary frames is chosen from the corrosivity of the environment and the required durability under ISO 12944, or the equivalent national guidance (AS 4312 and AS 2312.1 in Australia, SSPC/AMPP practice in North America). Typical options:

Slip-critical faying surfaces, field-weld zones and embedded areas are masked or coated only as the design allows. See paint and coating systems.

Documentation, packing and quotation

Deliverables include frame design calculations, anchor bolt plan with base reactions, erection drawings, shop drawings, mill test certificates to EN 10204 3.1 traceable to piece marks, weld inspection records and, on request, an IFC model. Frames are packed with timber dunnage and lashing in 40 ft high-cube containers or on flat racks for members longer than about 12 m.

A quotation can be prepared quickly when the enquiry states the project location and the code to be used. Please send:

1. Frame geometry: span, eave height, roof slope, bay spacing and frame type.
2. Loads and code, including any crane, mezzanine or collateral loads.
3. Connection philosophy (pinned or fixed bases) and anchor bolt preferences.
4. Required finish and the interface with the secondary framing supplier, if not WSC.

World Steel returns a priced scope with a clear inclusions and exclusions list, the design basis assumed and a typical lead time. Enquiries go through the export supply team in Ho Chi Minh City.