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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.

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.

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

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

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 · Report a correction · Companion guide updated .

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.

  1. What does two L four by four by three eighths mean?
  2. Two L means two structural angles used as a built-up pair.
  3. Each angle has two four-inch legs, and each angle is three eighths of an inch thick.
  4. The plain AISC database entry represents a back-to-back pair. Other entries can add a suffix for separation.
  5. Together, these two angles weigh nineteen point six pounds per foot and have a combined area of five point seven two square inches.
  6. The pair's behavior depends on separation, connected legs, stitch plates or fasteners, and its end connections.
  7. Two angles do not act as one by magic. Check eccentricity, slenderness, connectors, loads, and applicable code.
  8. Explore double-angle properties at Quantum Steel Design.

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