W12x19 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W12x19 is an American wide-flange beam 12.2 inches (309.9 mm) deep with a 4.01 in (101.9 mm) flange, weighing 19 pounds per foot (28.3 kg/m) — that is what the "19" in the designation means. All values below are the standard AISC published section properties used in US structural design, with metric equivalents alongside.
Typical uses: floor and roof framing, columns, headers, and general steel construction. For a quick stiffness check, see the deflection example below or open the beam calculator with your own span and load.
W12x19: cross-section drawn to scale from the AISC dimensions (d 12.2, bf 4.01, tw 0.235, tf 0.35 in)Dimensions
| Depth d | 12.2 in (309.9 mm) |
| Flange width bf | 4.01 in (101.9 mm) |
| Web thickness tw | 0.235 in (6 mm) |
| Flange thickness tf | 0.35 in (8.9 mm) |
Weight & Cross-Section
| Weight per foot | 19 lb/ft (28.3 kg/m) |
| 20 ft bar | 380 lb |
| 40 ft bar | 760 lb |
| Area A | 5.57 in² (35.9 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 130 in⁴ (5,411 cm⁴) |
| Section modulus Sx | 21.3 in³ (349 cm³) |
| Radius of gyration rx | 4.82 in |
| Moment of inertia Iy | 3.76 in⁴ (157 cm⁴) |
| Section modulus Sy | 1.88 in³ (31 cm³) |
| Radius of gyration ry | 0.82 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|
| W12x16 | 12 × 3.99 | 16 | 103 | 17.1 | −16 % | −21 % |
| W12x19 (this page) | 12.2 × 4.01 | 19 | 130 | 21.3 | — | — |
| W12x22 | 12.3 × 4.03 | 22 | 156 | 25.4 | +16 % | +20 % |
Deflection example
A simply supported W12x19 spanning 20 ft with a 10 kip point load at midspan deflects 0.76 in (E = 29,000 ksi, Ix = 130 in⁴). The L/360 serviceability limit for this span is 0.67 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W12x19 beam weigh?
W12x19 weighs 19 pounds per foot (28.3 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 380 lb and a 40 ft bar 760 lb.
What are the dimensions of a W12x19?
W12x19 is 12.2 in (309.9 mm) deep with a 4.01 in (101.9 mm) wide flange. The web is 0.24 in thick and the flanges are 0.35 in thick. Note the actual depth differs from the nominal W12 label — always design with the actual value.
What are the dimensions of a W12x19 in mm?
W12x19 is 309.9 mm deep with a 101.9 mm wide flange; the web is 6 mm and the flange 8.9 mm thick. In metric section properties: Ix = 5,411 cm⁴, Sx = 349 cm³.
How much does a W12x19 weigh in kg?
28.3 kg per meter. A 6 m bar weighs 170 kg and a 12 m bar 339 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W12x19?
About the strong axis, Ix = 130 in⁴ (5,411 cm⁴) with section modulus Sx = 21.3 in³. About the weak axis, Iy = 3.76 in⁴ and Sy = 1.88 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W12x19 or W12x22 — what does one size up change?
W12x22 is about 16% heavier (22 vs 19 lb/ft) but about 20% stiffer (Ix 156 vs 130 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