Hot Rolled H Beam AS/NZS 3678 Grade 350 Universal Column Steel Section Welded Building Frame

Hot Rolled H Beam AS/NZS 3678 Grade 350 Universal Column Steel Section Welded Building Frame

This hot rolled H beam is supplied to AS/NZS 3678 Grade 350 and used as a universal column steel section in welded building frames for Australian and New Zealand projects. The member carries a minimum yield strength of 350 MPa, is delivered with mill test certification per heat number, and can be cut, drilled and primed to the structural drawing before shipment.

Frames are built from two routes. A hot rolled universal column section suits standard profiles and repeat bays where speed matters. A welded built up H beam fabricated from AS/NZS 3678 Grade 350 plate suits non standard depth, wider flange, long span or heavy load cases where a rolled profile would be oversized. Both routes deliver the same 350 MPa minimum yield structural steel member and can be combined in one frame package.

Why Grade 350 Matters in an Australian or New Zealand Frame

Grade 350 is the working grade for most portal frame columns, rafters and mezzanine beams in the region. It offers a practical balance between strength and weldability, so a design can be lighter without losing load capacity. The grade is verified per heat number rather than per shipment, which means the chemistry and mechanical properties behind the 350 MPa figure can be traced back through the mill certificate for each member delivered.

For cold climate sites and members under dynamic load, impact tested options are available. Grade 350L0 provides 27 J Charpy impact energy at 0 degrees C, and Grade 350L15 provides 27 J at minus 15 degrees C.

Material and Mechanical Properties

• Steel standard: AS/NZS 3678, hot rolled structural steel plates, floorplates and slabs
• Steel grade: Grade 350
• Minimum yield strength: 350 MPa
• Tensile strength: 450 MPa
• Elongation: approximately 20 percent, dependent on plate thickness
• Impact grade options: Grade 350L0 and Grade 350L15
• Section type: hot rolled H beam and universal column section, or welded built up H section from Grade 350 plate

Section and Detail Options

• Section depth and flange width selected to suit span and load, not limited to a standard catalogue
• Length cut to order to match the project cutting list, no fixed stock length forced on the design
• Edge supplied as mill edge or sheared edge
• Holes for base plates, splices and connections drilled to drawing
• Stiffener plates, end plates, gussets and cleats welded to the column section
• Surface supplied as rolled, shot blasted or shop primed
• Hot dip galvanizing coordinated when the project specification requires it

Fabrication and Quality Control

• Incoming plate matched against AS/NZS 3678 Grade 350 mill certificate before cutting
• CNC cutting of flange and web components to the structural cutting list
• Submerged arc and MIG welding of built up H beams and welded column sections
• Weld procedure qualification and welder qualification records kept on file
• Straightness, flange squareness and web alignment checked against AS/NZS 3678 tolerance
• Dimensional and visual report issued before shipment, third party inspection welcome
• Every member match marked and numbered for site erection sequence

Typical Applications

• Portal frame columns and rafters for industrial sheds, warehouses and workshops
• Multi storey steel building frames and mezzanine floor beams
• Commercial steel buildings, showrooms and aircraft hangar structures
• Pre engineered building primary framing members
• Conveyor gantries, mining plant support structures and equipment skids
• Bridge girders and heavy fabricated steel structure assemblies
• Replacement columns and transfer beams for existing steel frames

Packing and Delivery

• Members bundled by section type and marked with project item numbers
• Timber dunnage between layers to protect primed surfaces
• Steel strapping and edge protection for container loading
• Flat rack and break bulk options for members beyond container limits
• Loading plan and packing list issued with the shipping documents

Buyer Questions

Is AS/NZS 3678 the correct standard for a hot rolled H beam?
AS/NZS 3678 covers hot rolled structural steel plates, floorplates and slabs. Welded built up H beams are fabricated from AS/NZS 3678 Grade 350 plate, while hot rolled universal column sections are supplied to the AS/NZS 3679.1 Grade 350 equivalent where the design specifies a rolled profile. Both routes give a 350 MPa minimum yield member accepted on Australian and New Zealand projects.

What is the difference between Grade 350, 350L0 and 350L15?
Grade 350 is the base structural grade with 350 MPa minimum yield strength. Grade 350L0 adds Charpy impact testing of 27 J at 0 degrees C. Grade 350L15 adds 27 J impact testing at minus 15 degrees C for colder service conditions.

Should the frame use hot rolled sections or welded built up beams?
Hot rolled universal column sections are economical for standard profiles and fast delivery. Welded built up H beams from Grade 350 plate are more flexible when non standard depth, wide flange, long span or heavy load is required, and make stiffener and connection integration easier during fabrication.

Can the whole building frame be supplied, not only the column?
Yes. Columns, rafters, purlins, bracing, base plates and anchor bolts can be fabricated and match marked as one welded building frame package.

Request a Section Schedule

Send the structural drawings or cutting list and we will reply with the section schedule, fabrication scope and delivery plan for your AS/NZS 3678 Grade 350 hot rolled H beam and universal column requirements.

Related products: Industrial Steel Buildings, Commercial Steel Buildings, Structural Steel Fabrications, Pre Engineered Building, Multi Storey Steel Building, Aircraft Hangar Buildings, Steel Framing Systems.