Product Overview
Galvanized steel sheet is the quiet workhorse of light construction and fabrication. It is the substrate under roofing and cladding, the metal behind ducting and HVAC runs, the sheet in cable trays, appliance panels, drums, switch boxes and a hundred general sheet-metal jobs. It is also the item most often bought on price alone - and that is exactly where a thin zinc coating or a rough surface shows up six months later as red rust.
We supply hot-dip galvanized steel sheet to ASTM A653, JIS G3302 (SGCC) and EN 10346, in plain sheet and cut-to-length sheet, with the thickness, width, zinc coating mass and surface finish agreed before the order is placed. The same sheet is the substrate behind our prepainted (PPGI) and colour-coated products, so if your project needs the coated finish later, the base material is already familiar ground for us.
Kennen Steel International Co., Ltd. is a China-based steel trading company and a first-tier mill agent. We do not run a factory. We buy direct from mills we know, hold them to the specification you agree, and manage the export side end to end - three decades of steel trading in China and a vetted network of source mills is what stands behind every order.
Most of our GI sheet goes to building-material distributors, HVAC and ducting fabricators, hardware traders and steel service centres across Africa, Southeast Asia and the Middle East - buyers who need a consistent coating weight, flat sheet, honest packing and paperwork that clears customs without a fight.
Key Advantages
Direct mill supply, not a resold catalogue
We buy from the mills and we check what they make. The zinc coating mass and the thickness on the packing list are the ones we agreed, and if a batch does not meet the specification it does not ship. You are buying mill material with someone accountable for the order.
Coating weight matched to the exposure, not to a default
Zinc is the whole point of GI sheet, and coating weight is where it is won or lost. Indoor ducting and painted panels do not need the same coating as coastal roofing. Tell us where the sheet is going and we will quote the coating class that lasts there, confirmed per order rather than guessed.
Plain sheet and cut-to-length from one source
Sheet, cut-to-length and coil supply in the same order, so you are not splitting a container between two suppliers and two sets of tolerances. Cut lengths and widths are made to your requirement, confirmed against your cutting list.
The substrate behind our prepainted products
GI sheet is what we prepaint. That means we understand the surface preparation, passivation and spangle questions that decide whether a coating sticks and a roof still looks right after two monsoons. Buy the base sheet from us now and the colour-coated version later from the same supply chain.
Flat, dry, and packed for the sea
Galvanized sheet that arrives wet, scratched or bent is scrap on arrival. Sheets ship on pallets or in wooden cases with moisture protection and steel strapping, agreed against the destination and handling conditions.
Documents that clear the gate
An EN 10204 3.1 mill test certificate per batch comes as standard, dimensional inspection is carried out against the cited standard, third-party inspection can be arranged on request, and we support the destination conformity paperwork some markets require, such as KEBS or PVoC.
Technical Specifications
| Item | Specification |
|---|---|
| Product Name | Hot-Dip Galvanized Steel Sheet (GI Sheet) |
| Standards | ASTM A653 / JIS G3302 (SGCC) / EN 10346; the standard applied is confirmed per order against your requirement |
| Grade | Commercial quality and structural grades per the cited standard (for example SGCC); grade confirmed per order |
| Thickness | 0.12-3.0 mm; exact range available per width confirmed per order |
| Width | 600-1500 mm; cut widths to your requirement, confirmed per order |
| Length | Plain sheet and cut-to-length sheet to your cutting list; coil also available |
| Zinc Coating | 30-275 g/m2 (both sides, total, as commonly expressed); coating class confirmed per order |
| Coating Designation | Per the cited standard, for example the Z-coating designation of ASTM A653 / EN 10346; the exact designation is stated on the mill certificate |
| Surface Finish | Regular spangle, minimized spangle; skin-passed where specified |
| Surface Treatment | Chromate passivated and/or oiled, per order; untreated on request |
| Form | Plain sheet / cut-to-length sheet; coil on request |
| Edge Condition | Mill edge or cut edge, per order |
| Dimensional Tolerance | In accordance with the cited standard; confirmed per size |
| Flatness | Per the cited standard; confirmed per size and thickness |
| Packing | Pallets or wooden cases with moisture protection, steel strapped for export |
| Certificate | EN 10204 3.1 mill test certificate per batch |
Thickness, width, zinc coating mass, surface finish and packing are confirmed against your requirement and destination before the order is placed. Coating weights quoted in g/m2 are total both sides unless agreed otherwise.
Step-by-Step Manufacturing Process
Galvanizing is the step everyone talks about, but the sheet that goes into the zinc bath decides the finished product. This is how the material we supply is made at the source mills.
- Steelmaking and pickling - the base steel is produced to the chemistry the grade calls for, then pickled to remove mill scale so the surface is clean and reactive.
- Cold rolling - the pickled strip is cold rolled to the target thickness. Thickness control here is what sets the tolerance you receive.
- Annealing - the strip is annealed to restore formability, so the sheet can be bent, profiled and roll-formed without cracking.
- Hot-dip galvanizing - the strip passes through a molten zinc bath and the coating mass is controlled at the air knife. This step sets the coating weight in g/m2 and the spangle.
- Skin passing and tension levelling - the coated strip is skin-passed to improve surface quality and flatness, and to minimise the spangle where a smoother finish is required.
- Surface treatment - chromate passivation and/or oiling is applied as agreed, to control storage staining and to prepare the surface where the sheet will later be prepainted.
- Cutting and packing - the strip is cut to sheet or to your cut-to-length requirement, inspected, then palletised or cased with moisture protection and steel strapping.
Quality Assurance & Certificates
- EN 10204 3.1 mill test certificate per batch - chemistry and mechanical properties, with coating mass where reported
- Dimensional inspection against the cited standard (thickness, width, length)
- Coating mass check against the agreed coating class
- Surface inspection for spangle, coating defects, scratches and staining
- Third-party inspection available on request (SGS, BV, Intertek)
- Documentation support for destination conformity schemes (for example KEBS or PVoC)
- Every shipment is checked against the agreed specification before it leaves, so what lands matches what was ordered
Core Applications
- Roofing and cladding substrate, and roofing sheets
- HVAC and ducting fabrication
- Cable trays, trunking and electrical enclosures
- Appliance panels and white goods
- Drums, containers and general metal packaging
- General sheet-metal fabrication, gutters, flashing and trim
- Base sheet for prepainted and colour-coated (PPGI) products
- Ceiling grids, partitions and light steel framing components
FAQ
What is the difference between GI sheet and PPGI?
GI sheet is the galvanized base - zinc coating on steel, left as it is. PPGI is that same galvanized sheet with a paint system applied on top, which is what gives you colour. GI is the substrate for our prepainted and colour-coated products, so if you need colour later, the base material comes from the same supply chain.
Which zinc coating weight should I order?
It depends on where the sheet goes. Coated and indoor applications can use a lighter coating; outdoor, humid and coastal work needs more zinc because that is what buys the time before rust. We work in the 30-275 g/m2 range as commonly quoted, and the class is confirmed per order once we know the exposure and the standard you are working to.
Can you supply cut-to-length sheet to my cutting list?
Yes. Cut-to-length sheet is made to your required length and width, and it is confirmed against your cutting list before the order is placed. Plain sheet and coil are also available if that suits your line better.
What surface finish do you offer?
Regular spangle as standard, and minimized spangle with skin passing where a smoother surface is required - for example when the sheet will be painted or formed into a visible panel. Passivation and oiling are agreed per order; tell us how the sheet will be stored and used and we will match the treatment to it.
Will the sheet rust in transit or in storage?
Galvanized sheet is protected by the zinc, but how it is packed and how long it sits in a humid port both matter. We ship with moisture protection and strapping and agree the packing against the destination. Once it arrives, store it dry and off the ground and keep it ventilated.
Do you provide certificates and inspection?
Yes. Every batch ships with an EN 10204 3.1 mill test certificate covering the details we have agreed. Third-party inspection (SGS, BV, Intertek) can be arranged on request, and we can support destination conformity documentation such as KEBS or PVoC where your market requires it.
Can you match a specification other than ASTM A653 or JIS G3302?
EN 10346 and other standards can be supplied on request. Send us the standard and the grades you need and we will confirm before you commit. Where a detailed standard question is still open, we will say so rather than guess.
Are you the manufacturer?
No. We are a China-based steel trading company and a first-tier mill agent. We buy direct from vetted source mills, verify the coating weight and dimensions, and manage the export - surface treatment, packing, certificates and shipping. You get mill material with someone accountable for the order.
What is the minimum order quantity?
It depends on the specification and whether you are taking sheet, cut-to-length or coil. Tell us the sizes and the destination and we will confirm the practical minimum for that combination.
