Why Per-Tonnage Rates Don’t Work in U.S. Steel Detailing

Steel detailing is a highly specialized process that requires precision, experience, and close coordination between engineers, fabricators, and contractors. One pricing model that detailers sometimes consider is per-tonnage rates, where the cost of detailing is based solely on the weight of the detailed steel.

While this method may seem straightforward, it fails to reflect the actual workload, complexity, and resources required for steel detailing. In the U.S. steel industry, per-tonnage rates can lead to underestimation of detailing costs, inefficiencies, and disputes over project scope. Below are key reasons why this pricing model is flawed.

1. Geometric Complexity of Structures

The geometry of a structure plays a crucial role in the complexity of detailing. Weight alone doesn’t capture how difficult a structure is to model and detail . Consider these examples:

Example 1: A small structure with radial elements, such as spiral staircases or curved arches, requires significantly more time for modeling and detailing than a larger but straightforward structure made of straight beams and plates.

Example 2: Complex bent plates or double-curved elements (such as dome cladding or storage tanks) require precise 3D modeling, additional calculations, and consideration of fabrication tolerances.

A structure with a lower total weight but high geometric complexity will require far more detailing hours than a heavier, but simple, box-like structure. Per-tonnage pricing does not account for this distinction, leading to unrealistic pricing and undervaluation of detailing efforts.

2. Number of Components Per Ton

Weight alone does not reflect the number of elements that must be detailed. Two structures with the same weight can have vastly different detailing workloads.

• A one-ton beam with simple end connections might require minimal detailing effort.
• Conversely, one ton of steel consisting of hundreds of small plates, brackets, stiffeners, and gusset plates requires significantly more detailing effort, as each piece needs individual shop drawings, and connection details.

When pricing is based solely on tonnage, complex and heavily detailed structures become unprofitable for detailers, while straightforward, repetitive “copy-paste” projects may result in excessive pricing. This imbalance makes per-tonnage pricing unsustainable.

3. Precision and Quality Requirements

Different projects demand different levels of precision, which directly impacts the time required for detailing. The per-tonnage model assumes all detailing is equal, which is far from reality.

• High-precision projects (miscellaneous steel or feature stairs) require tight fabrication tolerances, custom detailing, and extensive checking processes.
• Lower-precision projects (e.g. typical structural steel frame) allow for larger tolerances, reducing detailing time.
• Some projects demand extensive clash detection, coordination with other trades, and compliance with stringent fabrication and erection standards, all of which increase detailing complexity.

A pricing model based on steel weight does not account for the variations in quality and precision requirements. Detailers working on high-precision projects under per-tonnage rates often face undervalued labor costs and unrealistic deadlines.

4. Material and Technology Considerations

Different steel materials and fabrication methods influence the difficulty of detailing, yet per-tonnage pricing does not take these into account.

• Architecturally Exposed Structural Steel (AESS), for example, demands a higher level of precision and attention to aesthetics—such as smooth welds, concealed bolts, and tight tolerances—which significantly affects how details are modeled and documented.
• Laser-cut components, 3D-formed plates, and non-standard profiles demand additional modeling and detailing work to ensure accurate fabrication.
• Projects incorporating hybrid materials (e.g., steel with glass, aluminum, or composites) require additional coordination between detailing teams and suppliers, increasing project complexity.

A pricing model that ignores these material-based complexities results in mispriced projects and financial strain on detailers.

5. Organizational and Workflow Issues

Steel detailing is not just about creating drawings—it involves coordination, communication, and revision management throughout the project lifecycle. These organizational and logistical factors add workload that per-tonnage pricing fails to reflect:

Design Revisions & RFIs

Changes in design often require rework, additional coordination, and updates to drawings. A per-tonnage model does not factor in these unpredictable changes, leading to disputes over extra costs.

Coordination with Fabricators & Erectors

Some projects require weekly progress meetings, additional submittals, and constant updates, all of which increase detailing time beyond what a weight-based price can cover.

Custom Client Standards

Different clients have unique shop drawing requirements, connection preferences, and software output, which influence detailing workload. A fabricator with highly specific shop preferences will require more effort from detailers than one using standard AISC practice.

Under a per-tonnage model, these organizational aspects are often overlooked, resulting in financial losses and strained relationships between detailers and fabricators.

6. Impact on Project Profitability and Quality

Per-tonnage pricing creates unbalanced workloads and financial instability for detailers, ultimately impacting the overall quality of steel detailing. Some major risks include:

• Underbidding Complex Projects

Detailers pricing per ton may end up taking on projects with excessive complexity, leading to significant losses.

• Rushed Work and Lower Quality

When detailing time is underestimated, teams may be forced to rush their work, increasing the likelihood of errors that lead to fabrication and erection issues.

• Disputes Over Extra Work

Unforeseen complexities often lead to disputes between fabricators and detailers over what should be included in the per-ton rate and what qualifies as an extra charge.

A more realistic and transparent pricing model is necessary to avoid these pitfalls.

Alternative Pricing Models for Steel Detailing

Given the flaws of per-tonnage pricing, here are more effective alternatives:

Hourly Rates

Works well for projects with evolving designs or uncertain scope, ensuring fair compensation for actual time spent.

Fixed Project Pricing

Suitable for well-defined projects, allowing fabricators to budget accurately while ensuring detailers are paid for their expertise.

Hybrid Models

A mix of fixed pricing for predictable work and hourly rates for revisions ensures fairness and flexibility.

While per-tonnage rates may seem like a convenient way to estimate detailing costs, it fails to reflect the true complexity and effort required for steel detailing in the U.S. industry. Geometry, component count, precision, materials, coordination, and project-specific challenges all play a significant role in determining the workload. A more adaptive pricing model—whether hourly, fixed, or hybrid—ensures fair compensation, accurate project planning, and higher-quality steel detailing.

Collaborating with detailers under a transparent and realistic pricing model is the best way forward for fabricators looking to streamline their detailing process while maintaining accuracy and efficiency.

Learn more about steel detailing best practices and industry insights at ESD Solutions.