W21x93 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W21x93 is an American wide-flange beam 21.6 inches (548.6 mm) deep with a 8.42 in (213.9 mm) flange, weighing 93 pounds per foot (138.4 kg/m) — that is what the "93" 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 | 21.6 in (548.6 mm) |
| Flange width bf | 8.42 in (213.9 mm) |
| Web thickness tw | 0.58 in (14.7 mm) |
| Flange thickness tf | 0.93 in (23.6 mm) |
Weight & Cross-Section
| Weight per foot | 93 lb/ft (138.4 kg/m) |
| 20 ft bar | 1,860 lb |
| 40 ft bar | 3,720 lb |
| Area A | 27.3 in² (176.1 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 2,070 in⁴ (86,160 cm⁴) |
| Section modulus Sx | 192 in³ (3,146 cm³) |
| Radius of gyration rx | 8.7 in |
| Moment of inertia Iy | 92.9 in⁴ (3,867 cm⁴) |
| Section modulus Sy | 22.1 in³ (362 cm³) |
| Radius of gyration ry | 1.84 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W21x83 | 21.4 × 8.36 | 83 | 1,830 | 171 | −11 % | −12 % |
| W21x93 (this page) | 21.6 × 8.42 | 93 | 2,070 | 192 | — | — |
| W21x101 | 21.4 × 12.3 | 101 | 2,420 | 227 | +9 % | +17 % |
Deflection example
A simply supported W21x93 spanning 35 ft with a 10 kip point load at midspan deflects 0.26 in (E = 29,000 ksi, Ix = 2,070 in⁴). The L/360 serviceability limit for this span is 1.17 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W21x93 beam weigh?
W21x93 weighs 93 pounds per foot (138.4 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 1,860 lb and a 40 ft bar 3,720 lb.
What are the dimensions of a W21x93?
W21x93 is 21.6 in (548.6 mm) deep with a 8.42 in (213.9 mm) wide flange. The web is 0.58 in thick and the flanges are 0.93 in thick. Note the actual depth differs from the nominal W21 label — always design with the actual value.
What are the dimensions of a W21x93 in mm?
W21x93 is 548.6 mm deep with a 213.9 mm wide flange; the web is 14.7 mm and the flange 23.6 mm thick. In metric section properties: Ix = 86,160 cm⁴, Sx = 3,146 cm³.
How much does a W21x93 weigh in kg?
138.4 kg per meter. A 6 m bar weighs 830 kg and a 12 m bar 1,661 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W21x93?
About the strong axis, Ix = 2,070 in⁴ (86,160 cm⁴) with section modulus Sx = 192 in³. About the weak axis, Iy = 92.9 in⁴ and Sy = 22.1 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W21x93 or W21x101 — what does one size up change?
W21x101 is about 9% heavier (101 vs 93 lb/ft) but about 17% stiffer (Ix 2,420 vs 2,070 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