2 x 5 Rectangular Tube: An Essential Structural Component
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- publisher
- Tianjin Yuantai Derun steel pipe manufacturing group Ltd.
- Issue Time
- Oct 11,2023
Summary
In various industries, the demand for sturdy and versatile structural components is critical. One such component that has gained widespread usage is the 2 x 5 rectangular tube.
Key Takeaways
* Wall thickness typically runs 2.0 - 6.0 mm; weight per meter ranges from ~5.5 kg/m (2 mm) to ~15.6 kg/m (6 mm).
* Produced by ERW cold forming at Yuantai Derun, in black, or hot-dip galvanized finishes.
* Compliant with ASTM A500, EN 10219, JIS G3466, GB/T 6728 and certified to ISO 9001 / CE.
I. What Is a 2 x 5 Rectangular Tube?
A 2 x 5 rectangular tube (also written 2x5 RHS) is a hollow structural section (HSS) with a 2-inch by 5-inch rectangular cross-section — 50.8 x 127 mm. In metric markets, the equivalent size most often procured is 50 x 125 mm — a practical rounding that Yuantai Derun supplies as a standard metric option. As a steel pipe manufacturer, Yuantai Derun produces it in carbon steel (Q235 / Q355) and galvanized finishes via ERW cold forming. The long face gives a high section modulus along one axis, which is why it is the size most often specified for frames, racking, and trailer chassis where a flat bearing face and directional stiffness matter more than a square profile would provide.
II. 2 x 5 Rectangular Tube Dimensions & Weight
The table below covers the most commonly ordered specifications. Weight is calculated from the steel cross-sectional area at a density of 7.85 g/cm³.
| Property | 2 x 5 Rectangular Tube |
| Nominal size (imperial) | 2" x 5" (50.8 x 127 mm) |
| Metric equivalent (commonly procured) | 50 x 125 mm (non-imperial metric size) |
| Wall thickness | 2.0 - 6.0 mm (typical); up to 8.0 mm on request |
Weight per meter(50.8 x 127 mm) | ~5.5 kg/m (2 mm) | ~8.1 kg/m (3 mm) | ~10.7 kg/m (4 mm) | ~15.6 kg/m (6 mm) |
Weight formula(Yuantai Derun standard) | kg/m = (P/3.14 − t) × t × 0.0246615 | per piece (kg) = kg/m × L(m) where P = outer perimeter = 2 × (long + short side), t = wall (mm), L = length (m) |
Corner radius | Typically 2t - 3t (cold-formed RHS) |
Standards | ASTM A500 Gr B/C, ASTM A501, EN 10219, EN 10210, JIS G3466, GB/T 6728, AS 1163, CSA G40.21 |
Common grades | Q235, Q355, S235, S355 |
Worked example: 50 x 125 mm, 2.0 mm wall, 6 m length → (345/3.14 − 2) × 2 × 0.0246615 × 6 ≈ 31.9 kg per piece (~0.032 t). The metric 50 x 125 mm size yields a weight within about 1-2% of the 50.8 x 127 mm figures above — close enough for most structural estimates.
III. Applications of 2 x 5 rectangular tubes
The 2 x 5 size sits in a sweet spot: wide enough to span as a primary rail, narrow enough to nest tightly in a frame. Typical uses include:
- Solar mounting structures & photovoltaic support racks
- Trailer and truck chassis sub-frames
- Warehouse racking uprights and beams
- Building frames, mezzanines, and curtain-wall mullions
- Machinery guards, conveyor structures, and automation frames
- Furniture and architectural handrails
IV. Advantages of 2 x 5 rectangular tubes
Compared with square or round sections of similar weight, the rectangular profile offers directional stiffness: the 5-inch axis resists bending where the load runs along it, while the flat faces simplify bolted connections and panel mounting. Because it is hollow, it delivers high strength-to-weight efficiency — you get the rigidity of a solid bar at a fraction of the mass and cost. Cold-formed ERW RHS also has consistent wall thickness and tight dimensional tolerances, which speeds fabrication and reduces weld prep.
V. Manufacturing process of 2 x 5 rectangular tubes
ERW production of 2 x 5 rectangular tube at Yuantai Derun's tube mill: strip forming, longitudinal welding, sizing, and straightening.
At Yuantai Derun, 2 x 5 RHS is produced by ERW (electric resistance welding): strip steel is cold-formed into the 50.8 x 127 mm rectangular profile, longitudinally welded, then sized and straightened to EN 10219 tolerances. Customers can specify black (as-welded) or hot-dip galvanized finishes. Wall thickness typically runs from 2.0 mm to 6.0 mm, and every batch is verified by ultrasonic weld inspection and supplied with a Mill Test Certificate (MTC).
VI. Quality standards & certifications
Yuantai Derun 2 x 5 rectangular tubes are manufactured and inspected to the following standards:
Standards: ASTM A500 / A501, EN 10219 / 10210, JIS G3466, GB/T 6728 / 3094, AS 1163, CSA G40.20 / G40.21.
Certifications: CE, LEED, BV, PHD & EPD, BC1, ISO 9001, DNV, ABS, SGS, CNAS.
VII. Common variations of 2 x 5 rectangular tubes
Beyond the standard dimensions, 2 x 5 RHS is available in several variations to match project requirements:
Wall thickness: 2.0, 2.5, 3.0, 4.0, 5.0, 6.0 mm (and heavier on request)
Material grade: Q235 / Q355 (China), S235 / S355 (EN), Grade 350 (AS)
Finish: black, pre-galvanized, hot-dip galvanized, or painted
Custom lengths: cut-to-length and drilled/ punched per drawing
VIII. Maintenance and care of 2 x 5 rectangular tubes
Bare (black) RHS should be protected from prolonged moisture; for outdoor or corrosive environments, specify hot-dip galvanized or painted finishes. Periodic inspection for coating damage, cleaning of accumulated debris, and prompt touch-up of scratches will extend service life significantly. Galvanized sections typically require only periodic visual checks under normal conditions, but cut edges, drilled holes, and damaged coating areas should be touched up with a zinc-rich paint to preserve corrosion protection — bare cut faces are the most common failure point.
IX. 2 x 5 RHS vs Square / Round Tube
Against a square tube of equal weight, the 2 x 5 rectangle trades off-axis symmetry for higher bending resistance along its long axis — better when loads are directional. Against a round tube, it offers flat mounting faces and easier bolted joins, at a small penalty in torsional stiffness. Choose the rectangle when spanning, racking, or panel-mounting; choose round when the load is multi-directional or the member is rotated.
X. Conclusion
The 2 x 5 rectangular tube is a versatile, cost-effective structural section whose 50.8 x 127 mm profile delivers directional stiffness with low weight. Specified to ASTM A500 / EN 10219 and produced under ISO 9001 controls at Yuantai Derun, it is a dependable choice for frames, racks, and chassis across construction, solar, and transport applications.
FAQs
What are the weight and load-bearing capacity of a 2 x 5 rectangular tube?
The weight and load-bearing capacity of a 2 x 5 rectangular tube depend on the material used and the wall thickness. It is recommended to consult the manufacturer or refer to engineering specifications to determine the exact weight capacity.
Can 2 x 5 rectangular tubes be used in outdoor applications?
Yes. For outdoor or corrosive service, specify hot-dip galvanized or painted finishes and, where applicable, weather-resistant grades. Galvanized RHS performs well in exposed structural and solar-mounting applications with minimal maintenance.
Are there any limitations to using 2 x 5 rectangular tubes in construction projects?
While 2 x 5 rectangular tubes offer many advantages, there may be limitations in terms of structural design and compatibility with certain construction methods. It is advisable to consult with structural engineers to ensure the suitability of these tubes for specific construction projects.
Is 2 x 5 rectangular tube easy to weld?
Yes. Carbon steel RHS (Q235 / Q355, CEV below 0.45) welds readily with standard MIG/GMAW settings without pre-heating. Keep heat input moderate to avoid distorting the thin wall, and note that cold-formed corners are harder than the base steel.
Where can I purchase 2 x 5 rectangular tubes?
2 x 5 rectangular tubes can be purchased from various suppliers and distributors offering metal or construction materials. Local steel or metal fabrication companies, hardware stores, or online marketplaces are good sources to explore for purchasing these tubes.
This guide is written by the technical team at Yuantai Derun Group, an ERW/HSS producer certified to ISO 9001, CE, and SGS. Questions on sizing or specs? Browse our rectangular steel pipe sizes & specs.