The difference between lipped and unlipped steel stud framing sections

Currently, many engineering companies continue to base their certified engineering documentation on traditional unlipped stud designs, which were the industry standard for decades. Over the past few years, there has been a significant shift in the market. Lipped C-section steel studs have become the dominant profile used in construction due to their superior structural performance. 

Despite this industry shift, many engineering firms have not yet updated their methodologies to reflect the structural advantages of lipped profiles. As a result, there is often a gap between the actual products used on-site and the profiles assumed in the engineering documentation. 

At Frametec – Australian Engineered Steel Framing , we address this by working closely with external structural engineers who base their certifications and structural calculations on data and performance benchmarks specific to lipped C-section designs. This ensures that our framing systems are not only compliant with NASH and AS/NZS 4600 standards but are also engineered to reflect the true performance capabilities of the materials we manufacture. 

This report presents a comparative analysis of cold-formed steel stud sections with and without return lips, highlighting their structural performance, compliance with NASH standards, and practical application benefits.

It serves as an informative resource for clients and partners interested in optimized steel framing solutions. 

Stud section profiles 

Traditional (Unlipped) Stud: 

-Standard C-section without any return folds at the flange edges. 

-Simpler design is used primarily in non-structural or minimal-load applications.

 

Lipped Stud: 

-Enhanced C-section with 10–20mm return lips at flange edges. 

-Improves section stability and strength. 

Engineering advantages of lipped sections 

Structural Property	Unlipped Stud	Lipped Stud
Flexural Strength	Moderate	High
Torsional Rigidity	Lower	Enhanced
Local Buckling Resistance	Weak	Strong
Distortional Buckling	Susceptible	Minimized
Lateral Support Requirements	High	Reduced
Load Bearing Capacity	Moderate	Increased (25–40%)

Performance Metrics Based on AS/NZS 4600 & NASH Standards 

-Axial Capacity Increase: Lipped studs offer up to 37% more axial load capacity than unlipped equivalents. 

-Torsional Buckling Resistance: Improved by 30–50% depending on gauge and span. 

-Serviceability: Enhanced performance under wind and seismic loads. 

Practical implications 

Application Type	Recommended Stud Profile	Reason
Non-loadbearing Walls	Unlipped	Cost-effective simplicity
Loadbearing Walls	Lipped	High capacity & reduced bracing
Long Spans	Lipped	Improved stability
External Walls	Lipped	Better performance under wind

Compliance and standards 

–NASH Standard Part 1 & 2: Recognizes performance distinctions between profile types. 

–AS/NZS 4600: Lipped studs qualify for higher effective section properties. 

Conclusion 

Utilizing lipped steel studs significantly improves structural performance in residential and commercial framing systems. Frametec recommends lipped profiles for all structural applications to enhance safety, longevity, and cost-efficiency. 

Get in touch with Frametec for all your engineered steel needs in WA!

Phone: (08) 6182 4916