Steel Round Tube
Pre-Galvanized & Hot-Dip Galvanized Round Steel Pipe — Your Steel Round Tube Supplier
We supply premium steel round tube and hot dipped galvanized round tube with strict quality control. Ideal for industrial applications, construction, and structural projects. Factory direct pricing, global shipping.
What is Steel Round Tube?
Pre-Galvanized & Hot-Dip Galvanized Round Steel Pipe — Your Steel Round Tube Supplier
Steel round tube (also known as galvanized round steel pipe) is manufactured from steel strip/plate that is formed into a cylindrical shape and HF-welded along the seam. The galvanized coating provides excellent corrosion protection, making it ideal for both indoor and outdoor applications. As a trusted steel round tube supplier, Qiaosi Steel offers high-quality round tube with strict quality control for all industrial applications.
Qiaosi Steel supplies two main types: pre-galvanized (cold galvanized) — made from pre-galvanized steel strip; and hot-dip galvanized (HDG) — black pipe that undergoes hot-dip galvanizing after welding for maximum corrosion resistance.
Available sizes: OD 21.3 mm to 813 mm — Wall thickness 1.0 – 12.0 mm
Standards: ASTM A53 / EN 10219 / GB/T 3091 / JIS G3444.
Corrosion Resistant
Zinc coating protects against rust
Strong & Durable
High structural strength
Easy to Fabricate
Cut, weld, thread with ease
Smooth Finish
Clean appearance, paint-ready
100% Recyclable
Environmentally friendly
Galvanizing Methods — Steel Round Tube Supplier China
Pre-Galvanized (Cold) vs Hot-Dip Galvanized (HDG) — Steel Round Tube Supplier
❄️ Pre-Galvanized (Cold)
- Lower cost, smooth uniform finish
- Faster production, shorter lead time
- Good for non-exposed applications
🔥 Hot-Dip Galvanized (HDG)
- Superior corrosion protection (10–20+ years)
- Complete coverage including weld zone
- Rugged, long service life
Steel Round Tube Sizes — Specifications
Round Steel Pipe — Common Specifications — Steel Round Tube Supplier
| OD (mm) | Wall Thickness (mm) | Weight (kg/m) | Equivalent Inch Size | Available Finish |
|---|---|---|---|---|
| 🔹 Small Diameter (DN15 – DN50) | ||||
| 21.3 | 1.5 – 2.75 | 0.73 – 1.26 | ½″ | Pre-Galv / HDG |
| 26.7 | 1.5 – 2.87 | 0.93 – 1.69 | ¾″ | Pre-Galv / HDG |
| 33.5 | 1.5 – 3.25 | 1.18 – 2.42 | 1″ | Pre-Galv / HDG |
| 42.3 | 1.5 – 3.25 | 1.51 – 3.13 | 1¼″ | Pre-Galv / HDG |
| 48.3 | 1.5 – 3.5 | 1.73 – 3.87 | 1½″ | Pre-Galv / HDG |
| 60.3 | 2.0 – 3.65 | 2.88 – 5.10 | 2″ | Pre-Galv / HDG |
| 🔸 Medium Diameter (DN65 – DN150) | ||||
| 76.1 | 2.0 – 4.0 | 3.66 – 7.11 | 2½″ | Pre-Galv / HDG |
| 88.9 | 2.5 – 5.0 | 5.33 – 10.35 | 3″ | Pre-Galv / HDG |
| 101.6 | 2.5 – 5.0 | 6.11 – 11.91 | 4″ | Pre-Galv / HDG |
| 114.3 | 3.0 – 5.0 | 8.23 – 13.48 | 4½″ | HDG |
| 139.7 | 3.0 – 5.0 | 10.11 – 16.61 | 5½″ | HDG |
| 168.3 | 3.0 – 6.0 | 12.23 – 24.02 | 6″ | HDG |
| 🔹 Large Diameter (DN200 – DN400) | ||||
| 219.1 | 4.0 – 8.0 | 21.21 – 41.63 | 8″ | HDG |
| 273.0 | 5.0 – 8.0 | 33.04 – 52.28 | 10″ | HDG |
| 323.9 | 5.0 – 8.0 | 39.32 – 62.32 | 12″ | HDG |
| 355.6 | 5.0 – 8.0 | 43.23 – 68.57 | 14″ | HDG |
| 406.4 | 6.0 – 10.0 | 59.25 – 97.75 | 16″ | HDG |
| 🔸 Extra Large (DN450 – DN800) | ||||
| 457 | 6.0 – 10.0 | 66.73 – 110.23 | 18″ | HDG |
| 508 | 6.0 – 10.0 | 74.28 – 122.81 | 20″ | HDG |
| 610 | 6.0 – 12.0 | 89.37 – 176.97 | 24″ | HDG |
| 711 | 8.0 – 12.0 | 138.69 – 206.85 | 28″ | HDG |
| 813 | 8.0 – 12.0 | 158.81 – 237.03 | 32″ | HDG |
Weight calculated at carbon steel density 7.85 g/cm³. HDG adds approx. 3–6% extra weight depending on zinc coating thickness.
Available surface treatments: black (plain), pre-galvanized, hot-dip galvanized, painted, oiled.
Steel Round Tube Applications — Industrial Uses
Where Steel Round Tube Is Used — Industrial Applications
Steel Structures
Columns, trusses, bracing
Handrails & Guardrails
Stair railings, bridge barriers
Water & Gas Supply
Plumbing, fire sprinkler lines
Greenhouses
Frame structures
Fencing & Gates
Security fencing, panel frames
Solar Mounting
Support structures
Industrial Piping
Steam, air, oil lines
Marine & Port
Piles, fenders, piers
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