StructureCalcsHSS20X4X3/8
Rectangular HSS · AISC Shapes Database v15.0 · United States
HSS20X4X3/8 is a rectangular hollow structural section 508 × 102 mm with a 9.5 mm wall, weighing 86.5 kg/m. The dimensions below are the published AISC Shapes Database v15.0 values; the drawing is generated from them.
Rectangular HSS are cold-formed tubes that AISC tabulates on the design wall thickness (0.93 × nominal) — the note beside the derived table explains what that convention does to the numbers.
Analyse this section, or combine it with plates and other shapes.
Open HSS20X4X3/8 in the Section CalculatorFree, no sign-up, runs in your browser.
Published dimensions
| Property | Metric | Imperial |
|---|---|---|
| Overall depth, d | 508 mm | 20.00 in |
| Overall width, b | 102 mm | 4.00 in |
| Wall thickness, t | 9.5 mm | 0.375 in |
| Mass per metre | 86.5 kg/m | 58.1 lb/ft |
| Area, A | 10,323 mm² | 16.00 in² |
| Second moment, Ix | 273,464,047 mm⁴ | 657.0 in⁴ |
| Second moment, Iy | 19,812,616 mm⁴ | 47.6 in⁴ |
Derived section properties
Integrated from the section's own outline including its outside corner radii, whose arcs are integrated analytically rather than approximated by facets. For HSS20X4X3/8 the computed area agrees with the published value to 0.42% and Ix to 0.12%. Where a value is also published, the published one above is the one to quote.
AISC tabulates hollow-section properties on the design wall (tdes = 0.93 tnom, per AISC 360), while the published mass reflects the nominal wall — which is why mass and area here differ by about 7% by convention, on every AISC hollow section.
| Property | Value |
|---|---|
| Elastic modulus, Sx | 1,075,320 mm³ |
| Elastic modulus, Sy | 389,531 mm³ |
| Plastic modulus, Zx | 1,462,203 mm³ |
| Plastic modulus, Zy | 438,376 mm³ |
| Radius of gyration, rx | 163.0 mm |
| Radius of gyration, ry | 43.9 mm |
S is the elastic modulus and Z the plastic modulus, following AISC 360. Australian and British practice reverse the letters.
Neighbouring sizes
Where these numbers come from
Published AISC Shapes Database v15.0 values. How StructureCalcs verifies its numbers · Understanding steel section properties · Query this section over the API