Source: https://www.quantumsteeldesign.com/videos/2l4x4x3-8/ Steel video · 0:48 # What Does 2L4x4x3/8 Mean? Double Angles Explained Decode the 2L4x4x3/8 double-angle designation and understand why separation, connectors, eccentricity, and stability define the built-up member. What you will learn - 2L: Two structural angles. - 4: First leg: 4 in. - 4: Second leg: 4 in. - 3/8: Each angle thickness. Published August 7, 2026 [Watch on YouTube ↗](https://www.youtube.com/watch?v=06j7EWecUVc) [Watch the Short ↗](https://www.youtube.com/shorts/KCsMtMCJJjw) Practical context ## How the steel information fits the project workflow The plain database entry represents a back-to-back pair; suffixes may identify separation in other entries. The built-up member requires deliberate connection and stability design. Continue with the data ### 2L4x4x3/8 shape reference Move from the video explanation to the related reference, dimensions, properties, tools, and learning context. [Open related reference](https://www.quantumsteeldesign.com/steel-tools/shapes/2l4x4x3-8/) Companion reading and practice ## Which double-angle arrangement does the record describe? A double-angle label identifies two angles, but the full reference record can also distinguish their arrangement and separation. Those configuration details matter when interpreting the listed properties. Keep the exact database designation with the drawing reference. Do not assume that the properties for one pair arrangement describe every assembly made from the same two angles. The depicted profile is reference geometry, not a connection detail. ### Try it with a sample Inspect the complete designation and any configuration suffix before comparing two double-angle records. [Read the double-angle reference](https://www.quantumsteeldesign.com/steel-tools/shapes/2l4x4x3-8/) Examples are fictional learning exercises. This companion text adds context to the video; the transcript below records the narration. Primary sources ## References and further reading - [AISC Shapes Database v16.0](https://www.aisc.org/aisc/publications/steel-construction-manual/aisc-shapes-database-v160/) Use the edition and requirements adopted for the project. These references support further reading; a short video does not reproduce the complete standards. Published by Quantum Steel Design. [Sources and editorial approach](https://www.quantumsteeldesign.com/about/#editorial-approach) · [Report a correction](https://www.quantumsteeldesign.com/contact/) · Companion guide updated September 28, 2026. Accessible transcript ## What Does 2L4x4x3/8 Mean? Double Angles Explained transcript The visible transcript makes the video content available to people and search systems without requiring playback. - What does two L four by four by three eighths mean? - Two L means two structural angles used as a built-up pair. - Each angle has two four-inch legs, and each angle is three eighths of an inch thick. - The plain AISC database entry represents a back-to-back pair. Other entries can add a suffix for separation. - Together, these two angles weigh nineteen point six pounds per foot and have a combined area of five point seven two square inches. - The pair's behavior depends on separation, connected legs, stitch plates or fasteners, and its end connections. - Two angles do not act as one by magic. Check eccentricity, slenderness, connectors, loads, and applicable code. - Explore double-angle properties at Quantum Steel Design. Keep watching ## More structural steel detailing and fabrication videos. [View the complete video library](https://www.quantumsteeldesign.com/videos/) [0:55](https://www.quantumsteeldesign.com/videos/blank-steel-data-not-zero/) August 8, 2026AI-assisted detailing explainer ## Why Blank Steel Data Is Not Zero Learn why blank, zero, unknown, and not-applicable are different data states—and how silent conversion can make incomplete steel information appear valid. [Watch with transcript](https://www.quantumsteeldesign.com/videos/blank-steel-data-not-zero/) [Watch Short ↗](https://www.youtube.com/shorts/Iv2DZp-aR58) [0:55](https://www.quantumsteeldesign.com/videos/w12x26-vs-w12x40/) August 7, 2026Steel explainer ## W12x26 vs W12x40: Same Depth Family, Different Beam Compare W12x26 and W12x40 dimensions, weight, flange width, stiffness, and connection implications before treating two W12 beams as equivalent. [Watch with transcript](https://www.quantumsteeldesign.com/videos/w12x26-vs-w12x40/) [Watch Short ↗](https://www.youtube.com/shorts/eWLSHfLqtfM) [0:55](https://www.quantumsteeldesign.com/videos/pipe6std/) August 6, 2026Steel explainer ## What Does Pipe 6 STD Mean? Structural Pipe Explained Decode Pipe 6 STD, including nominal pipe size, the actual 6.625-inch outside diameter, standard weight, Schedule 40 geometry, and wall thickness. [Watch with transcript](https://www.quantumsteeldesign.com/videos/pipe6std/) [Watch Short ↗](https://www.youtube.com/shorts/ffZI__zFKuI)