Design drawings alone are not enough to actually fabricate a steel-framed building in the shop and erect it accurately on site. What is needed are drawings that take the building conditions shown in the design drawings and translate them into the information required for actual fabrication, such as the shapes and dimensions of steel members, connection methods, bolt positions, and welding.

These are “steel fabrication drawings.”

Steel fabrication drawings are not simply design drawings redrawn in CAD. They must be prepared by confirming the design conditions and studying steel connection detailing and fabrication methods, while taking into account processing, assembly, and welding in the shop, as well as erection on site. In recent years, there has also been a growing number of cases in which not only 2D drawings but also digital data usable in the fabrication process, such as BIM models and NC data, are handled end to end.

This article offers a clear explanation of steel fabrication drawings, from the basics to the main types, the preparation workflow, the software used, and BIM and data integration.

I. What Are Steel Fabrication Drawings?

1. The Role of Steel Fabrication Drawings

Steel fabrication drawings take design information, such as architectural and structural design drawings, and turn it into the concrete information needed to actually fabricate the steel. Design drawings show the structure of the building as a whole, the arrangement of members, cross-sections, and so on. Steel fabrication drawings, on the other hand, build on that information to set out in concrete terms how each member is to be processed and assembled.

For example, the following information is required:

• Member types and sizes
• Member lengths and dimensions
• Bolt positions and hole positions
• Shapes of splices and beam-column connections
• Connection components such as gusset plates
• Welding information
• Member numbers and marks
• Material
• Information required for processing

In other words, steel fabrication drawings can be thought of as “drawings that bring the designed steel to a state where it can actually be fabricated in the shop”.

2. Differences Between Design Drawings, Construction Drawings, and Steel Fabrication Drawings

To understand steel fabrication drawings, it is important to know how they differ from design drawings and construction drawings.

In practice, however, naming conventions and how drawings are categorized may differ from company to company and project to project. Steel fabrication drawings are also sometimes called “shop drawings.”

What matters is not just the name, but whether the information needed to carry the design through to actual steel fabrication is properly organized.

3. The Flow from Design to Fabrication and Erection

In general, steel fabrication proceeds as follows:

“Design drawings / structural drawings ➞ Study and preparation of steel fabrication drawings ➞ Drawing review and approval ➞ Processing and fabrication ➞ Quality inspection ➞ Transport ➞ Erection on site”

For this reason, steel fabrication drawings must take into account not only “whether they are correct as drawings” but also whether the steel can actually be fabricated and built.

II. Main Types of Steel Fabrication Drawings

Steel fabrication drawings come in various types depending on their purpose. Here we introduce the most typical ones.

1. Study & Standard Drawings

These drawings are used to confirm the conditions of the building as a whole and the steel connection detailing before full-scale production of fabrication drawings begins.

For example:

• Member arrangement
• Reference dimensions
• Relationships between columns and beams
• Approach to connections
• Interfaces with other trades
• Anchor bolt positions

These and similar items are checked.

Depending on the project, identifying issues at this stage can reduce revisions in later processes. It is especially important to check the interfaces between the steel and other components early on.

2. General Drawings

General drawings are used to understand the steel configuration of the building as a whole.

Typical examples include:

• Anchor bolt plans
• Steel framing plans
• Framing elevations
• Floor-by-floor layout plans

and more.

General drawings are organized so that the positional relationships of members and the overall configuration of the building can be checked. Rather than depicting individual members in detail, they serve as drawings for accurately grasping the overall steel configuration.

3. Detail Drawings (Shop Drawings)

Detail drawings set out, in concrete terms, the information needed for the actual processing and assembly of each steel member, such as columns and beams.

For example:

• Column detail drawings
• Beam detail drawings
• Beam-column connection detail drawings
• Splice detail drawings
• Plate details
• Bolt holes
• Welding information

and more.

A simple way to think of it: general drawings confirm the overall positional relationships, and detail drawings make each member concrete enough to be fabricated.

4. Full-Scale & Erection Marking Drawings

Full-scale drawings set out in more concrete detail the dimensions and shapes needed to process and fabricate members. “Erection marks” are also important for managing steel members.

Assigning marks and numbers to each member makes it easier to track:

• Members to be fabricated
• Members to be processed
• Items subject to inspection
• Members to be erected on site

and more.

Especially in large buildings with many members, it is important to correctly match drawings with member information.

5. Drawings for Secondary Members & Ancillary Materials

Beyond the main steel structure, drawings and data may also be prepared for the secondary members required for the building and the construction work.

For example:

• Deck plates
• Studs
• Fireproofing
• Opening reinforcement
• Other secondary members

and similar items.

Looking beyond the main steel structure and taking into account its interfaces with surrounding components is a key factor in the quality of fabrication drawings.

III. Steel Fabrication Drawings: From Preparation to Delivery

Steel fabrication drawings are not simply a matter of preparing drawings and delivering them. The project conditions are confirmed, the drawings are prepared, checked, and revised, and, where necessary, carried through to fabrication data.

A typical workflow is as follows.

1. Review of Requirements & Documents

First, the design drawings, structural drawings, and related documents are reviewed.

At this stage, the following are reviewed:

• Building size
• Number of stories
• Steel quantity
• Materials used
• Connection methods
• Standards and specifications
• Software to be used
• Delivery deadline
• Required deliverables

These and similar items are checked.

It is also important to clarify in advance any conditions that cannot be determined from the drawings alone.

2. Study & Connection Detailing Review

Next, the steel connection detailing is checked based on the design conditions.

In particular:

• Column-to-beam connections
• Beam-to-beam interfaces
• Braces
• Secondary members such as stairs
• Openings
• Interfaces with other trades

These and similar items are checked.

Finding problems at this stage reduces rework after fabrication begins.

3. Preparing Steel Fabrication Drawings

Once the conditions have been confirmed, general drawings, detail drawings, and other drawings are prepared. Depending on the project, 2D CAD may be used, or a model may first be built in 3D BIM/CAD and the drawings generated from it.

What matters is not the software itself, but that the fabrication information ultimately required is accurately organized.

4. Checking & Revision

The completed drawings are checked for dimensions, members, connections, bolts, marks, and so on. If design changes or check-backs arise, the drawings are updated.

In steel fabrication, a single change can affect multiple drawings and members, so it is important to track changes accurately.

5. Organizing Erection Marks & Fabrication Data

Once the drawings are finalized, member numbers and erection marks are organized, and data for use in fabrication is prepared as needed.

Depending on the project, the following may be required:

• NC data
• DSTV
• NC1
• DXF
• Member lists
• Quantity tables
• Various schedules and reports

and more.

Consistently organizing not only 2D drawings but also data usable in later processes streamlines coordination with the fabrication process.

6. Delivery

Finally, the drawings and data are delivered in the format specified for the project. Deliverables vary by project, but may include:

For example:

• Steel Fabrication Drawings
• Detail Drawings
• Erection Marking Drawings
• BIM Models
• NC data
• Member & Quantity Data
• Clash Detection Reports

and more.

For this reason, when commissioning steel fabrication drawings, confirming at the outset not only “which drawings will be produced” but also “what should ultimately be delivered” is essential.

IV. Main Deliverables of Steel Fabrication Drawing Work

Steel fabrication drawing work involves a wide range of data beyond the drawings themselves.

1. Steel Fabrication Drawings

This is the core deliverable. The drawings the project requires are prepared, such as general drawings, detail drawings, full-scale drawings, and erection marking drawings.

2. Processing & Fabrication Data

This is data for use in the fabrication process. Typical formats include:

• NC1
• DSTV
• DXF

and more.

The required formats vary depending on the equipment and software used, so they need to be confirmed in advance.

3. Members, Quantities & Schedules

To manage steel members, the following may be compiled:

• Member lists
• Steel quantities
• Bolt quantities
• Member numbers
• Other schedules and reports

and more.

4. BIM Models & Verification Documents

In projects that use BIM, the following may also be produced:

• Steel BIM models
• IFC data
• 3D models
• Clash detection results
• Corrective proposals
• Check-back response documents

and other materials.

In this way, in today's steel fabrication, what matters is not just “making drawings” but handling drawings, models, and fabrication data as a connected whole.

V. Main Software Used for Steel Fabrication Drawings

The software used for steel fabrication drawings varies with the scale and purpose of the project and the client's specifications.

1. S/F REAL4

S/F REAL4 is one of the dedicated systems used in work related to steel fabrication. It lets you work with steel members, connections, and more, and carry them through to the drawings and data needed for fabrication.

In steel fabrication work in Japan, what matters is not only the software used but also handling data in line with each company's standards and operating practices.

2. Tekla Structures

Tekla Structures is software used for 3D modeling of structures, detailing, BIM workflows, and more. Its key feature is that steel models are built in 3D, and members, connections, and other elements can be managed within the model.

It also supports data exchange with a variety of formats such as IFC and AutoCAD, and can be used for integration with other BIM/CAD environments. Trimble's 2026 documentation also describes data exchange with IFC2x3, AutoCAD, Revit, and others.

3. AutoCAD & Jw_cad

For creating and editing 2D drawings, general-purpose CAD such as AutoCAD and Jw_cad may be used. Particularly for projects involving revisions and additions to existing drawings, 2D CAD can be the better fit.

4. Revit and Other BIM Software

When linking steel information with a BIM model of the entire building, Revit and similar tools may also be used. That said, BIM does not always mean using a specific piece of software.

It is important to choose the right software based on the environment specified for the project and data integration with upstream and downstream processes.

VI. BIM Adoption and Data Integration for Steel Fabrication Drawings

In steel fabrication today, a growing number of projects use not only 2D drawings but also 3D models and fabrication data.

With BIM, steel members can be reviewed as a 3D model, making it easier to check positional relationships and connection detailing between members that are hard to grasp from 2D drawings alone.

1. Clash Detection

One of the most typical uses of BIM models is clash detection.

For example:

• Clashes between beams and MEP
• Clashes between columns and MEP piping
• Clashes between steel and openings
• Interfaces with other trades

These and similar items are checked.

If problems are found, the clash locations are organized and corrective proposals are considered as needed.

2. Linking Drawing and Model Information

Rather than using the 3D model merely as a “model for checking appearance,” managing it together with member information and attribute information makes the data easier to use in later processes as well.

For example, information can be linked in a chain such as “BIM model ➞ Member information ➞ Fabrication drawings ➞ Member and quantity information ➞ NC data ➞ Fabrication.”

Of course, actual data integration methods and available formats differ depending on the software used, the shop's equipment, and the project specifications.

3. BIM Is Not Just About “Going 3D”

The purpose of introducing BIM is not simply to turn 2D drawings into 3D. What matters is the perspective of “how that 3D model will be used in subsequent processes”.

Will it be used for clash detection, for quantity management, or for producing fabrication drawings, or carried all the way through to NC data? Once the purpose is clear, the required model accuracy and attribute information change accordingly.

VII. Benefits of Outsourcing and Offshoring Steel Fabrication Drawings

In steel fabrication drawing work, companies sometimes turn to external design and fabrication drawing teams due to heavier workloads during peak periods or staff shortages.

Outsourcing is not merely a matter of sending work outside; it also has the benefit of letting in-house resources focus on more important work.

1. Easier to Secure Resources During Peak Periods

When projects pile up, your in-house team alone may not be able to handle every drawing. Using external resources lets you supplement your capacity for just the period you need.

2. Outsource Only the Work You Need

There is no need to outsource every process.

For example:

• A full set of steel fabrication drawings
• Detail drawings only
• BIM model creation
• Clash detection only
• NC data creation
• Revisions to existing projects

Options like these let you outsource only the scope your project needs.

3. Request Work in Your Specified Software

For steel fabrication drawings, the client or steel fabricator sometimes specifies the software to be used. Therefore, when choosing an outsourcing partner, it is important to check not only “whether they can produce steel drawings” but also “whether they can work with the specified software, formats, and standards”.

For example, a team that can work with S/F REAL4, Tekla Structures, AutoCAD, Jw_cad, Revit, and more to suit project conditions is easier to integrate into your existing workflow.

4. Key Points When Using Offshore Resources

When using an overseas engineering team, rather than judging on labor cost alone, it is important to check:

• Understanding of Japanese drawings and specifications
• How instructions are shared
• Communication in Japanese
• Checking system
• Handling of revisions and check-backs
• Data management
• Security
• Deadline management

and similar points.

For steel fabrication drawings in particular, what matters is not only drafting skill but also a setup that allows ongoing communication based on an understanding of Japanese design and fabrication rules.

NOOVASTEEL has built a team structure tailored to project conditions, covering everything from steel fabrication drawings to BIM models, clash detection, and fabrication-related data. We confirm the software, deliverables, deadlines, checking scope, and other details in advance, and can work to the scope you require.

VIII. Summary

Steel fabrication drawings are essential drawings that carry the content of the design drawings through to actual steel fabrication.

They involve more than simply drawing member shapes and dimensions, extending to:

• Confirming design conditions
• Studying steel connection detailing
• Creating general drawings and detail drawings
• Organizing full-scale layouts and erection marks
• Creating processing and fabrication data
• BIM models and clash detection
• Data integration with the fabrication process

It is important to prepare them with the entire project in mind, all the way through these steps. Today, work also goes beyond 2D CAD, using software such as S/F REAL4, Tekla Structures, and Revit as appropriate to link drawings, BIM, and fabrication data.

When outsourcing steel fabrication drawings, rather than simply choosing “a company that can draw,” it is important to check the software used, scope of services, quality control, communication, and checking system.

With steel fabrication drawings at its core, NOOVASTEEL supports the work required for steel fabrication, including BIM models, clash detection, and processing and fabrication data, tailored to each project. If you are considering outsourcing steel fabrication drawings or adopting BIM, we will first review your current drawings, software, required deliverables, deadlines, and other details, and then propose the best way forward.