L8x4x1/2 — Dimensions, Weight & Section Properties
Steel angle (L-shape) per ASTM A6 / AISC Steel Construction Manual
L8x4x1/2 is a hot-rolled steel angle with a 8 in (203.2 mm) long leg and a 4 in (101.6 mm) short leg, 0.5 in thick, weighing 19.6 pounds per foot (29.2 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 | 8 in (203.2 mm) |
| Short leg | 4 in (101.6 mm) |
| Thickness t | 0.5 in (12.7 mm) |
Weight & Cross-Section
| Weight per foot | 19.6 lb/ft (29.2 kg/m) |
| 20 ft bar | 392 lb |
| 40 ft bar | 784 lb |
| Area A | 5.75 in² (37.1 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 38.6 in⁴ (1,607 cm⁴) |
| Section modulus Sx | 7.48 in³ (123 cm³) |
| Radius of gyration rx | 2.59 in |
| Moment of inertia Iy | 6.75 in⁴ (281 cm⁴) |
| Section modulus Sy | 2.15 in³ (35 cm³) |
| Radius of gyration ry | 1.08 in |
Compared with the neighbouring sizes
| Shape | legs (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| L8x4x1/2 (this page) | 8 × 4 | 19.6 | 38.6 | 7.48 | — | — |
Deflection example
A simply supported L8x4x1/2 spanning 13 ft with a 10 kip point load at midspan deflects 0.71 in (E = 29,000 ksi, Ix = 38.6 in⁴). The L/360 serviceability limit for this span is 0.43 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a L8x4x1/2 angle weigh?
L8x4x1/2 weighs 19.6 pounds per foot (29.2 kg/m). A 20 ft bar weighs 392 lb and a 40 ft bar 784 lb.
What are the dimensions of a L8x4x1/2?
L8x4x1/2 has a 8 in long leg and a 4 in short leg, both 0.5 in thick. Angle legs are measured outside-to-outside, and both legs share the same thickness.
What are the dimensions of a L8x4x1/2 in mm?
L8x4x1/2 has a 203.2 mm long leg and a 101.6 mm short leg, 12.7 mm thick. In metric section properties: Ix = 1,607 cm⁴, Sx = 123 cm³.
How much does a L8x4x1/2 weigh in kg?
29.2 kg per meter. A 6 m bar weighs 175 kg and a 12 m bar 350 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a L8x4x1/2?
About the strong axis, Ix = 38.6 in⁴ (1,607 cm⁴) with section modulus Sx = 7.48 in³. About the weak axis, Iy = 6.75 in⁴ and Sy = 2.15 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
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