L4x4x3/8 — Dimensions, Weight & Section Properties
Steel angle (L-shape) per ASTM A6 / AISC Steel Construction Manual
L4x4x3/8 is a hot-rolled steel angle with equal 4 in (101.6 mm) legs, 0.375 in thick, weighing 9.8 pounds per foot (14.6 kg/m). All values below are the standard AISC published section properties, with metric equivalents alongside.
Typical uses: bracing, lintels, shelf supports, frames, and connection material. Angles are weak about their minor axis — long unbraced angles need lateral restraint. For a quick check, see the deflection example below or open the beam calculator.
Dimensions
| Long leg | 4 in (101.6 mm) |
| Equal leg | 4 in (101.6 mm) |
| Thickness t | 0.375 in (9.5 mm) |
Weight & Cross-Section
| Weight per foot | 9.8 lb/ft (14.6 kg/m) |
| 20 ft bar | 196 lb |
| 40 ft bar | 392 lb |
| Area A | 2.86 in² (18.5 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 4.32 in⁴ (180 cm⁴) |
| Section modulus Sx | 1.5 in³ (25 cm³) |
| Radius of gyration rx | 1.23 in |
| Moment of inertia Iy | 4.32 in⁴ (180 cm⁴) |
| Section modulus Sy | 1.5 in³ (25 cm³) |
| Radius of gyration ry | 1.23 in |
Compared with the neighbouring sizes
| Shape | legs (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| L4x4x5/16 | 4 × 4 | 8.2 | 3.67 | 1.27 | −16 % | −15 % |
| L4x4x3/8 (this page) | 4 × 4 | 9.8 | 4.32 | 1.5 | — | — |
| L4x4x1/2 | 4 × 4 | 12.8 | 5.52 | 1.96 | +31 % | +28 % |
Deflection example
A simply supported L4x4x3/8 spanning 6 ft with a 10 kip point load at midspan deflects 0.62 in (E = 29,000 ksi, Ix = 4.32 in⁴). The L/360 serviceability limit for this span is 0.2 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a L4x4x3/8 angle weigh?
L4x4x3/8 weighs 9.8 pounds per foot (14.6 kg/m). A 20 ft bar weighs 196 lb and a 40 ft bar 392 lb.
What are the dimensions of a L4x4x3/8?
L4x4x3/8 has two equal 4 in (101.6 mm) legs, both 0.375 in thick. Angle legs are measured outside-to-outside, and both legs share the same thickness.
What are the dimensions of a L4x4x3/8 in mm?
L4x4x3/8 has two equal 101.6 mm legs, 9.5 mm thick. In metric section properties: Ix = 180 cm⁴, Sx = 25 cm³.
How much does a L4x4x3/8 weigh in kg?
14.6 kg per meter. A 6 m bar weighs 88 kg and a 12 m bar 175 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a L4x4x3/8?
About the strong axis, Ix = 4.32 in⁴ (180 cm⁴) with section modulus Sx = 1.5 in³. About the weak axis, Iy = 4.32 in⁴ and Sy = 1.5 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
L4x4x3/8 or L4x4x1/2 — what does one size up change?
L4x4x1/2 is about 31% heavier (12.8 vs 9.8 lb/ft) but about 28% stiffer (Ix 5.52 vs 4.32 in⁴). Going one step up within the same depth group is usually the cheapest way to cut deflection.
Values are entered from the governing standard’s published tables and cross-checked programmatically against its mass and section formulas before publication. Spotted an error? Write to advertising@metalabout.net — verified corrections ship within days. About