Buyers often ask for a price per ton, and fabricators often quote one. The trouble is that two prices per ton can describe very different deliverables, so the number on its own decides very little.
This guide explains what actually moves the cost of a steel structure package. It does not quote prices: rates depend on the market, the order and the terms, and they belong in a project-specific quotation.
The inputs that move the number
| Driver | Why it changes the price |
|---|---|
| Connection complexity | Plate work, stiffeners, weld volume and fitting time often matter more than the raw tonnage |
| Member size and weight | Heavier sections need different handling, cranes and sometimes different transport |
| Welding and inspection scope | Full-penetration welds and higher testing percentages add hours and inspection cost |
| Surface preparation and coating | Blast grade, coating system and dry film thickness, or galvanizing, change both material and process time |
| Material grade and source | Grade, impact class and availability at the time of order affect the steel price itself |
| Order size and repetition | Repeated identical members and stable batch sizes reduce handling and set-up per ton |
| Schedule | Compressed delivery windows require expediting, overtime or buying material on the spot market |
| Packing and loading | Bundling, protection, marking and open-top or flat-rack equipment all cost more than a plain bundle |
| Documentation and inspection regime | Third-party inspection, welder qualifications and record packages are real work, not paperwork overhead |
| Delivery terms | The Incoterm decides where the seller's cost stops, so the same structure priced FOB and DAP is not comparable |
Why the weight itself is not the whole story
Fabrication cost is driven by hours per ton, not by tons alone. A straightforward portal frame with repeated members and simple connections can be produced at a much lower cost per ton than a small package of heavily plated, fully welded, fully tested members with an awkward geometry.
- A light building with many small members can cost more per ton than a heavier building with fewer, simpler members.
- A small order carries the same set-up, drawing, inspection and coating overhead across fewer tons.
- Secondary steel, accessories and bolts are often quoted separately, which changes the effective rate per ton.
How to compare quotations by price
- Confirm the same supply scope in every quotation, including secondary steel, bolts, accessories and the envelope.
- Confirm the quoted tonnage and the member basis it came from.
- Confirm the coating system, the inspection scope and the document set.
- Confirm the Incoterm and named place.
- Compare the exclusion lists before comparing the rates.
- Check what happens to the rate if the tonnage changes after shop drawings: is the rate fixed, or does it move with the final weight?
What to send for a comparable price
- Drawings or a BOQ, plus the building use and dimensions.
- Design loads and the standard the project follows.
- Steel grade and coating requirement.
- Supply scope boundaries, and the accessory items expected.
- Packing, marking and delivery requirements, with the destination.
- Inspection and documentation requirements.
- Target delivery window and expected order size.
This guide describes general practice for steel structure projects. It is not a design, and it does not replace the specification or the engineer responsible for your project.