Secondary Steel in PEMB Systems: Channels, Angles & Tubing Sourcing Guide

While pre-engineered metal building manufacturers typically account for the primary frame and standard secondary framing system in the quoted building package, real projects often require additional channels, angles, and HSS tubing for canopies, mezzanines, equipment supports, bracing, connections, and field changes.

When that happens, procurement teams have to deal with sourcing the right secondary steel for PEMB systems. This article is a guide that might help you keep fabrication and erection schedules moving.

What Counts as Secondary Steel in a PEMB System?

A standard PEMB package commonly includes purlins and girts that span between the building’s primary rigid frames. These members are generally cold-formed C- or Z-sections engineered as part of the manufacturer’s building system.

Keep in mind those components do not necessarily cover every structural requirement that develops during a project. Hot-rolled channels, structural angles, and HSS tubing are commonly used as supplemental steel when framing requirements extend outside the manufacturer’s standard package. 

Applications may include:

• Canopies
• Mezzanines
• Equipment platforms
• Bracing
• Connection components
• Non-standard framing
• Field-driven modifications

The distinction matters during procurement. 

Purlins and girts generally come from the PEMB manufacturer as part of the engineered building package. Channels, angles, and tubing can often be sourced through a regional structural steel service center when the project requires additional material.

This can be particularly important when scope changes occur after the original PEMB package has already been released for production.

Structural Channels for PEMB Framing

Structural steel channels provide a relatively deep cross-section that makes them useful where the secondary framing member needs greater bending capacity than a lighter angle would typically provide. Common PEMB applications for structural steel channels include canopy framing, equipment supports, bracing, and supplemental framing around project-specific openings or structural features.

Two channel configurations commonly encountered are C-shapes, also called American Standard Channels, and MC shapes, also called Miscellaneous Channels. Common material grades include ASTM A36 and ASTM A572 Grade 50, depending on project requirements. The appropriate grade, section size, and connection design should always be confirmed against the project drawings and with the structural engineer or PEMB manufacturer.

For procurement teams and erectors, availability can be just as important as the section itself. Buying structural steel channels from available service-center inventory can reduce the need to wait for a new mill order. Cut-to-length capabilities can also reduce field cutting and help crews receive material closer to the dimensions required for installation.

Structural Angles for PEMB Connections and Bracing

Strucural steel angles are among the most versatile supplemental members used in metal building construction.

Common uses include:

• Base angles at eave and rake walls
• Clip connections
• Gussets
• Cross-bracing
• Light structural framing
• Supplemental connection components

ASTM A36 is commonly specified for structural angles, while galvanized material may be required for applications exposed to moisture, corrosive conditions, agricultural environments, or other conditions identified by the project design. 

Because angles use a simpler cross-section than channels, they can be an economical option for applications that do not require the additional bending performance of a channel.

That makes product selection important from both an engineering and procurement perspective. Specifying a heavier member than necessary can add material cost, while selecting a member that does not meet the engineered load requirement can create a much larger project problem.

Pro Tip: confirm the size, grade, finish, and connection requirements before ordering structural steel angles for a PEMB project.

HSS Tubing for Mezzanines, Canopies and Non-Standard Framing

Hollow Structural Sections, or HSS tubing, provide another option when PEMB secondary steel requirements extend beyond standard purlins, girts, angles, or channels.

Typical applications include mezzanine framing, canopy posts and beams, non-standard bay framing, and members used as part of wind or seismic bracing systems. HSS tubing is commonly produced to ASTM A500 specifications, including Grade B or Grade C depending on the required application and design.

One advantage of HSS tubing is its closed cross-section. The shape can provide useful torsional performance while also creating clean architectural lines. For that reason, HSS is frequently considered for exposed framing, particularly canopy and mezzanine applications where the finished appearance of the steel matters.

As with channels and angles, the exact HSS size, wall thickness, ASTM grade, and connection design should be determined by the project’s engineering requirements.

Specs and Coatings to Confirm Before You Order

Before requesting a quote for secondary steel PEMB systems, verify more than the member dimensions.

Important procurement details include:

• ASTM material grade
• Mill certification requirements
• Member size and length
• Galvanized or painted finish requirements
• Bolted or welded connection design
• Hole patterns, if applicable
• Required quantities
• Target delivery or field installation date

Coating requirements should match the project’s environment and specifications. Similarly, welded and bolted connections can create different fabrication and finish requirements.

Pro Tip: do not assume that one ASTM grade or coating is appropriate for every PEMB application. Confirm requirements with the structural engineer, project specifications, or PEMB manufacturer before placing the order.

Sourcing Checklist: What to Have Ready When You Call

A complete material request helps a steel supplier confirm inventory and provide a more useful quote.

Before contacting a supplier, have as much of the following information ready as possible:

• Member type
• Section size
• Required length
• Quantity
• ASTM grade, if specified
• Project location
• Target field or delivery date
• Galvanized or painted finish requirement
• Bolted or welded connection requirements
• Mill certification requirements

If the complete engineered material list is not available yet, provide a description of the application and the information you do have. Your supplier can then identify what additional details will be needed to accurately quote the material.

Check Brown Strauss’s in-stock inventory of channels, angles, and HSS tubing, or request a quote to confirm availability for your PEMB project.

Frequently Asked Questions

What is the difference between structural channel and structural angle in a PEMB?

Structural channel has a deeper C-shaped cross-section and is typically better suited to applications requiring greater bending strength, such as canopy framing and equipment supports. Structural angle is simpler and can be a more economical choice for lighter bracing, gussets, clip connections, and similar applications.

What ASTM grade is used for PEMB secondary steel?

Channels and angles are commonly available in ASTM A36 or ASTM A572 Grade 50. HSS tubing is commonly available to ASTM A500 Grade B or Grade C. The correct grade depends on the load, member design, and project requirements. Confirm the specification with the structural engineer or PEMB manufacturer before ordering.

Can Brown Strauss supply channels, angles, and tubing for the same PEMB project?

Yes. Brown Strauss stocks channels, structural angles, and HSS tubing at multiple U.S. locations and can supply multiple product types for a single PEMB project. Cut-to-length capabilities are also available for applicable orders.

Does Brown Strauss fabricate or design PEMB primary frames?

No. Brown Strauss is a structural steel service center, not a PEMB manufacturer. Brown Strauss supplies structural and supplemental steel, including channels, angles, and HSS tubing, that may be required alongside the manufacturer-engineered PEMB primary frame and standard secondary framing system.

Source Secondary Steel Without Adding Another Schedule Constraint

When a PEMB project requires supplemental framing beyond the manufacturer’s standard package, sourcing channels, angles, and HSS tubing does not need to become another project bottleneck.

Brown Strauss provides access to structural steel inventory from locations across the United States, helping PEMB manufacturers, erectors, and contractors source the secondary steel required for canopies, mezzanines, supports, bracing, connections, and field changes.

Check in-stock inventory or request a quote  to confirm material availability for your next PEMB project.