W12x65 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W12x65 is an American wide-flange beam 12.1 inches (307.3 mm) deep with a 12 in (304.8 mm) flange, weighing 65 pounds per foot (96.7 kg/m) — that is what the "65" 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.
Dimensions
| Depth d | 12.1 in (307.3 mm) |
| Flange width bf | 12 in (304.8 mm) |
| Web thickness tw | 0.39 in (9.9 mm) |
| Flange thickness tf | 0.605 in (15.4 mm) |
Weight & Cross-Section
| Weight per foot | 65 lb/ft (96.7 kg/m) |
| 20 ft bar | 1,300 lb |
| 40 ft bar | 2,600 lb |
| Area A | 19.1 in² (123.2 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 533 in⁴ (22,185 cm⁴) |
| Section modulus Sx | 87.9 in³ (1,440 cm³) |
| Radius of gyration rx | 5.28 in |
| Moment of inertia Iy | 174 in⁴ (7,242 cm⁴) |
| Section modulus Sy | 29.1 in³ (477 cm³) |
| Radius of gyration ry | 3.02 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W12x58 | 12.2 × 10 | 58 | 475 | 78 | −11 % | −11 % |
| W12x65 (this page) | 12.1 × 12 | 65 | 533 | 87.9 | — | — |
| W12x72 | 12.3 × 12 | 72 | 597 | 97.4 | +11 % | +12 % |
Deflection example
A simply supported W12x65 spanning 19 ft with a 10 kip point load at midspan deflects 0.16 in (E = 29,000 ksi, Ix = 533 in⁴). The L/360 serviceability limit for this span is 0.63 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W12x65 beam weigh?
W12x65 weighs 65 pounds per foot (96.7 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 1,300 lb and a 40 ft bar 2,600 lb.
What are the dimensions of a W12x65?
W12x65 is 12.1 in (307.3 mm) deep with a 12 in (304.8 mm) wide flange. The web is 0.39 in thick and the flanges are 0.61 in thick. Note the actual depth differs from the nominal W12 label — always design with the actual value.
What are the dimensions of a W12x65 in mm?
W12x65 is 307.3 mm deep with a 304.8 mm wide flange; the web is 9.9 mm and the flange 15.4 mm thick. In metric section properties: Ix = 22,185 cm⁴, Sx = 1,440 cm³.
How much does a W12x65 weigh in kg?
96.7 kg per meter. A 6 m bar weighs 580 kg and a 12 m bar 1,161 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W12x65?
About the strong axis, Ix = 533 in⁴ (22,185 cm⁴) with section modulus Sx = 87.9 in³. About the weak axis, Iy = 174 in⁴ and Sy = 29.1 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W12x65 or W12x72 — what does one size up change?
W12x72 is about 11% heavier (72 vs 65 lb/ft) but about 12% stiffer (Ix 597 vs 533 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