| Hot-Dip Galvanized Round Structural Tube | Steel tube is fabricated first and immersed in molten zinc, producing a metallurgically bonded coating on the external and accessible internal surfaces. | Common supply range: approximately 12.7–219.1 mm outside diameter and 0.8–8.0 mm wall thickness, depending on production capability and structural specification. | Coating requirements are normally specified by zinc mass or thickness. Minimum local coating thickness is commonly about 45–85 μm, depending on the steel thickness and governing standard. | Strong long-term atmospheric corrosion protection; suitable for outdoor service; the coating protects exposed steel through barrier and sacrificial action. | Outdoor frames, guardrails, agricultural structures, solar-support components, fences, walkways and general construction. | ISO 1461EN ISO 1461ASTM A123/A123MASTM A500 | Confirm whether the structural tube specification and the galvanizing specification are both required. Check vent and drain-hole design, thread protection, straightness and post-galvanizing dimensional tolerances. |
| Pre-Galvanized ERW Round Tube | Cold- or hot-rolled steel strip is zinc-coated in coil form and then roll-formed and welded into tube. | Common supply range: approximately 10–165 mm outside diameter and 0.6–3.2 mm wall thickness. | Common coating designations include Z120–Z275 g/m² total on both surfaces, equivalent to approximately 8–19 μm per side when evenly distributed. | Consistent surface appearance, efficient production, competitive cost and good protection for normally exposed surfaces. | Light structural work, greenhouse components, shelving, furniture frames, cable support systems, interior construction and general fabrication. | EN 10346ASTM A653/A653MJIS G3302 | Forming and welding can expose small areas at the seam or cut ends. Specify repair treatment for damaged areas and assess suitability for continuously wet, buried or highly corrosive environments. |
| Pre-Galvanized Square and Rectangular Hollow Section | Zinc-coated strip is roll-formed into square or rectangular hollow sections, usually using electric resistance welding. | Common supply range: approximately 15 × 15 mm to 200 × 200 mm square; rectangular sections commonly range from about 20 × 10 mm to 200 × 100 mm, with 0.8–8.0 mm wall thickness. | Typical commercial coating levels are about Z120–Z275 g/m² total on both sides; actual coating class depends on the ordered material grade and applicable standard. | Efficient load distribution, easy fabrication, clean appearance and convenient flat surfaces for mounting or connection. | Racking, partition frames, machinery guards, fencing, construction subframes, signage supports and light structural assemblies. | EN 10346EN 10219ASTM A500ASTM A653/A653M | Check corner radius, squareness, weld-zone appearance, diagonal dimensions and the condition of cut ends. For heavy outdoor exposure, a post-fabrication hot-dip coating may provide more complete coverage. |
| Hot-Dip Galvanized Square and Rectangular Structural Tube | Square or rectangular hollow section is fabricated and then hot-dip galvanized after forming and welding. | Common supply range: approximately 20 × 20 mm to 300 × 300 mm square and up to about 400 × 200 mm rectangular, with wall thicknesses commonly from 1.5–12 mm. | Coating thickness is determined by the steel thickness and the applicable galvanizing standard; typical minimum local values are often about 45–85 μm. | High durability for outdoor environments, better coverage of fabricated surfaces than pre-galvanized material and reduced need for repeated painting. | Bridges and access platforms, outdoor stairs, highway furniture, utility supports, agricultural buildings and coastal or industrial structures. | ISO 1461EN ISO 1461ASTM A123/A123MEN 10219 | Provide suitable vent and drain holes for closed sections. Allow for zinc buildup at corners and threaded areas, and verify lifting, handling and weld-repair procedures. |
| Electro-Galvanized Precision Tube | A zinc layer is deposited electrochemically after tube production, generally providing a smooth and uniform appearance. | Common supply range: approximately 6–100 mm outside diameter and 0.5–3.0 mm wall thickness. | Typical commercial coating thickness is approximately 5–25 μm, although the specified class may vary significantly by product standard and corrosion requirement. | Good dimensional control, smooth finish, suitable for indoor or mildly exposed applications and convenient for further forming or painting. | Automotive components, interior equipment, furniture, appliances, light-duty frames and precision fabricated parts. | ISO 2081ASTM B633EN 10152 | Usually less suitable than hot-dip galvanizing for severe outdoor, marine, buried or continuously wet service. Confirm passivation, salt-spray performance, surface class and post-forming corrosion protection. |
| Rigid Galvanized Steel Electrical Conduit | Steel conduit is zinc-coated to protect the raceway from corrosion; the coating arrangement can vary between external-only and external-plus-internal protection. | Common nominal sizes are approximately 16–63 mm, with wall thickness commonly around 1.2–3.5 mm, depending on the conduit classification. | Coating requirements depend on the conduit system. Hot-dip galvanized conduit generally provides a thicker, more durable coating than electro-galvanized conduit. | Mechanical protection for cables, fire-resistant metallic raceway, grounding continuity when correctly installed and good suitability for exposed installations. | Industrial buildings, commercial electrical systems, infrastructure projects, exposed cable routes and areas requiring robust mechanical protection. | IEC 61386-21IEC 61386-1EN 61386-21 | Check nominal size, thread form, coupling compatibility, internal burr control, corrosion category, grounding requirements and local electrical-code acceptance. |
| Galvanized Mechanical Tube for Fabrication | Low-carbon or alloy steel tube is produced for forming and fabrication, then supplied with either pre-galvanized or electro-galvanized protection. | Common supply range: approximately 8–120 mm outside diameter and 0.7–5.0 mm wall thickness. | Coating levels vary by process and purchase specification; pre-galvanized products commonly use Z120–Z275 g/m² total coating, while electro-galvanized products often use thinner zinc layers. | Good weldability and formability when the steel grade is selected correctly; suitable for repeatable component production. | Automotive brackets, equipment frames, seating structures, agricultural machinery parts, racks and fabricated assemblies. | EN 10346ISO 2081ASTM A653/A653MASTM B633 | Confirm steel chemistry, yield strength, elongation, bending radius, weld procedure, coating damage after fabrication and requirements for zinc-fume control during welding. |
| Galvanized Water and Utility Pipe | Steel pipe is normally hot-dip galvanized after manufacture, with zinc applied to the exterior and, where specified, the interior. | Common nominal pipe sizes range from approximately 15–150 mm, with wall thickness selected according to the pressure, service and regional pipe classification. | Coating requirements should be defined by the relevant pipe or galvanizing standard. Actual internal coverage and coating continuity must be verified separately. | Useful for certain utility, service and non-potable applications where mechanical strength and corrosion protection are required. | Compressed-air lines, agricultural utilities, fire-protection-related systems where approved, temporary services and non-potable water systems. | ISO 1461EN ISO 1461ASTM A123/A123MEN 10255 | Do not assume suitability for drinking water, hot water or chemical service. Confirm local health regulations, pressure rating, fluid compatibility, threaded-end protection and internal corrosion risk. |