By the LGS FrameX Team · Updated October 2026
Steel studs look similar on a pallet, but they do very different jobs. Knowing the difference between load-bearing and non-load-bearing studs helps owners, builders and estimators avoid expensive mistakes.
Non-load-bearing studs
Non-load-bearing studs form interior partitions and exterior curtain-wall backup that carry little more than their own weight, finishes and lateral loads such as wind or impact. They are commonly thinner material and are often produced to the ASTM C645 standard for non-structural framing.
Load-bearing studs
Load-bearing studs carry floor, roof and wall loads down to the foundation and must be designed by a licensed engineer. They are typically heavier gauge, spaced to suit the design, and braced and connected as detailed. Structural studs and track are commonly specified to ASTM C955 and designed under AISI framing standards.
How to tell them apart
Never guess from appearance. The structural drawings and the stud labeling, which can include thickness, size and manufacturer data, are what count. Heavier thickness in mils, deeper webs and different flange sizes are typical of structural members, but only the engineer of record can say what is load-bearing.
Why it matters for cost and schedule
Using structural members where partitions would do raises cost, and using light members where loads exist is a safety and code problem. Clear labeling at production, which modern roll-forming lines support, reduces mix-ups on site. See our steel stud gauge guide for thickness conversions.
Typical sizes and thicknesses
Steel studs are described by web depth, flange width, lip and material thickness. Common web depths run from about 1-5/8 inches for interior partitions up to 6 inches or more for exterior and structural walls, with flanges commonly around 1-1/4 to 2 inches. Thickness is stated in mils, where one mil is one thousandth of an inch. Light non-structural studs can be as thin as roughly 18 mils, while structural studs commonly run from about 33 mils up to 97 mils or more, depending on the loads.
| Use | Typical thickness | Who decides |
|---|---|---|
| Interior partitions | About 18 to 33 mils | Architect or designer |
| Exterior curtain-wall backup | About 33 to 54 mils | Engineer for wind loads |
| Load-bearing walls | About 33 to 97 mils or more | Engineer of record |
These ranges are general guides only. The stamped drawings always govern.
Common mistakes on site
The most common error is mixing members: a pallet of lighter partition studs ends up in a structural wall because it was closer to the work. Other frequent problems are missing bridging or bracing, screws that are too short or over-driven, cutting flanges or webs without engineer approval, and punching new holes outside the allowed service-hole zones. Labeling every member at the roll former and checking the label against the drawing before it is installed prevents most of these.
Inspection and documentation
Ask for mill certificates that confirm steel grade and galvanized coating, keep the product labels visible until inspection, and photograph connections before they are covered by sheathing. If the project is panelized, request shop drawings that show every panel with its member sizes and fastener schedule.
Frequently asked questions
Can I use non-load-bearing studs in a load-bearing wall?
No. Load-bearing walls must use members designed by an engineer for the loads they carry.
Are load-bearing steel studs always thicker?
They are typically heavier gauge, but the required size depends on the design, so rely on the structural drawings.
What standard covers structural steel studs?
Structural studs and track are commonly specified to ASTM C955 and designed using AISI cold-formed steel framing standards; your engineer will confirm the project requirements.
Related guides
Talk to LGS FrameX about your project
Tell us your building type, height and timeline, and our team will help you choose the right light gauge steel framing approach or Fx series machine.
