SS400 Material Hot Dipped Galvanized Steel Pipe/Tube

Product Overview

Material & Galvanizing Advantages

• Superior Weldability: SS400's low carbon content ensures reliable arc and resistance welding without preheat in most thicknesses. Galvanized surfaces can be welded directly using proper ventilation and technique.
• Uniform Zinc Coverage: Hot-dip galvanizing coats both external and internal surfaces of hollow sections, providing cathodic protection even at cut edges and scratch locations.
• Cold Bending Compatibility: SS400 tube can be bent, swaged, and flared after galvanizing for railing systems and greenhouse frames without zinc layer cracking in moderate-radius bends.
• High Adhesion: The iron-zinc alloy layer formed during immersion ensures the coating withstands handling, transport, and field installation without peeling or flaking.
• Maintenance-Free Longevity: Properly galvanized SS400 pipe provides 20–50 years of corrosion protection in rural atmospheres and 10–20 years in industrial or coastal environments, eliminating repainting cycles.

Application field:

Construction field: used for building structures, scaffolding, railings, roof drains, etc.

Water supply and drainage system: used for conveying tap water, sewage, hot water, etc.

Machinery manufacturing: used for manufacturing mechanical parts, brackets, pipes, etc.

Electric power engineering: used for utility poles, cable bridges, substation structures, etc.

Automobile manufacturing: used for car body frame, exhaust pipe, etc.

Chemical industry: used for pipelines conveying chemical media.

FAQ

Q: What is the difference between SS400 and Q235B for galvanized pipe?

A: SS400 (JIS G3101) and Q235B (GB/T 700) are nearly equivalent in chemistry and mechanical properties. SS400 has slightly less stringent phosphorus and sulfur limits in some interpretations, but both grades weld, bend, and galvanize identically. The choice usually depends on the customer's standard preference or project specification origin. We can supply either marking on the same physical product.

Q: How does hot-dip galvanized SS400 pipe differ from pre-galvanized (zinc-coated coil) pipe?

A: Hot-dip galvanizing applies zinc after the pipe is formed and welded, coating both the outside and inside surfaces with a thick, durable layer (typically 200–610 g/m²). Pre-galvanized pipe is formed from zinc-coated coil, leaving the weld seam and cut ends unprotected with only a thin zinc film (20–40 g/m²). For outdoor structural or water service applications, hot-dip galvanizing is strongly preferred for longevity.

Q: Can SS400 galvanized pipe be welded on-site without removing the zinc coating?

A: Yes, but proper safety measures are required. Welding through galvanized coating produces zinc oxide fumes that must be extracted or ventilated. The weld area should be ground clean of zinc within 10–20 mm of the joint for the best weld quality. Post-weld cold galvanizing compound or zinc-rich paint can restore corrosion protection at the weld.

Q: What is the difference between "pipe" and "tube" in your product range?

A: In our offering, "pipe" generally refers to round hollow sections with nominal diameters and schedule wall thicknesses used for fluid conveyance and structural columns. "Tube" encompasses both round and square/rectangular hollow sections (RHS/SHS) typically specified by precise OD and wall dimensions for fabrication, framing, and mechanical applications. Both are available in SS400 hot-dip galvanized finish.