Hot-Dip Galvanized Unequal Angle Steel | L40×25 – L200×125
Unequal-leg angle steel hot-dip galvanized to EN ISO 1461, ASTM A123 or GB/T 13912 with a zinc coating from 30 to 700 g/m² on both surfaces. Supplied from L40×25 to L200×125, cut, punched or drilled to your drawing before dipping so no bare steel is left in the finished part.
Product Overview
Galvanized unequal angle starts as a hot-rolled asymmetric angle, which is then immersed in a molten zinc bath so that a metallurgically bonded zinc-iron coating forms over the whole surface, including the cut ends, hole walls and edges. The coating is not a paint film that can chip away from the steel beneath it: it is an alloy layer that corrodes sacrificially, protecting the steel even where the surface is later scratched.
The asymmetric section is the reason this product exists. Where a bracket, cleat or one-sided support is exposed to weather, an unequal galvanized angle gives the load path the section it needs without the dead weight of a symmetric angle, and the coating removes the need for painting, inspection and repainting over the life of the structure.
Coating weight is specified rather than guessed. We supply from 30 g/m² for dry indoor duty up to 700 g/m² for severe marine and industrial atmospheres, quoted as the total on both surfaces. Sizes run from L40×25 up to L200×125 over the standard thicknesses, in 6 m, 9 m and 12 m lengths, cut to your cutting list before galvanizing.
Specifications & Size Range
Galvanized unequal-leg range. Mill lengths are 6 m, 9 m and 12 m; cut-to-length, punched and drilled processing is carried out before galvanizing so the finished part is fully coated. Coating weight is nominated on the enquiry against the service environment.
| Size group | Common sizes (long × short, mm) | Leg thickness (mm) | Coating weight (g/m², both surfaces) | Typical use |
|---|---|---|---|---|
| Small unequal | L40×25, L45×28, L50×32 | 3 / 4 / 5 | 60 – 275 | Outdoor brackets, light frames, garden and fencing details |
| Medium unequal | L56×36, L63×40, L75×50 | 5 / 6 / 8 | 180 – 400 | Solar racking, guard-rail brackets, plant supports |
| Large unequal | L80×50, L90×56, L100×63 | 6 / 8 / 10 | 275 – 500 | Pole and tower details, coastal supports, walkway frames |
| Heavy unequal | L125×80, L140×90, L160×100, L200×125 | 9 / 10 / 12 / 14 / 16 | 275 – 700 | Marine structures, heavy outdoor frames, bridge details |
| Processed galvanized | Any size above | as above | as specified | Punched and drilled members, dipped after processing |
Tolerances
Zinc coating to GB/T 13912, EN ISO 1461, ASTM A123 / A153 and JIS H8641, quoted in g/m² total on both surfaces, with a working guide of about 7 µm of coating thickness per 100 g/m². Base section dimensions and straightness follow GB/T 706. Coating mass is measured on a sample basis per lot and a coating test report is issued with the shipment.
Steel Grades & International Equivalents
All grades below are supplied with a mill test certificate. The right-hand column shows the material type and the Chinese standard the grade is produced to; the middle columns give the nearest recognised equivalent in other national standards. Exact equivalence for a specific project should be confirmed on the enquiry.
| GB (China) | ASTM / AISI (US) | EN (Europe) | JIS (Japan) | DIN (Germany) | Type / Standard |
|---|---|---|---|---|---|
| Q235B + hot-dip galvanized | A123 / A153 (ASTM) | EN ISO 1461 | JIS H8641 | DIN 50976 | Hot-dip galvanized structural steel (GB/T 13912) |
| Q235B | A36 / A283 Gr.C | S235JR (EN 10025-2) | SS400 (JIS G3101) | St37-2 | Carbon structural steel (GB/T 700) |
Grade Notes
- Q235B + hot-dip galvanized — Zinc coating of 30–700 g/m² gives 5–30+ years of atmospheric corrosion protection depending on thickness and environment.
- Q235B — The workhorse structural grade in China. Fully weldable, excellent cost-performance, the closest Chinese equivalent to ASTM A36 / EN S235JR.
Chemical Composition (%, ladle analysis)
Typical specification limits. Actual heat values are reported on the mill test certificate supplied with every shipment.
| Grade | C | Si | Mn | P max | S max | Other elements |
|---|---|---|---|---|---|---|
| Q235B | ≤0.20 | ≤0.35 | ≤1.40 | ≤0.045 | ≤0.045 | — |
Mechanical Properties
Minimum values at room temperature unless stated. ReL = yield strength; Rp0.2 = 0.2% proof stress; Rm = tensile strength; A = elongation after fracture.
| Grade | Yield (ReL) | Proof (Rp0.2) | Tensile (Rm) | Elongation A | Impact / others | |
|---|---|---|---|---|---|---|
| Q235B + hot-dip galvanized | — | — | — | — | — | Coating 30–700 g/m² (both sides), made to order Adhesion per GB/T 13912 bend test |
| Q235B | ≥235 MPa | — | 370–500 MPa | ≥26% | +20 °C, ≥27 J | — |
Standards & Documents
- GB/T 13912 — hot-dip galvanized coatings on fabricated iron and steel articles
- EN ISO 1461 / ISO 1461 — hot-dip galvanized coatings (international equivalent)
- ASTM A123 / A153 — zinc (hot-dip galvanized) coatings on iron and steel products
- JIS H8641 — hot-dip zinc coatings (Japanese equivalent)
- GB/T 706 — base unequal angle dimensions, shape and tolerance
- Zinc bath to EN 1179 (Zn ≥ 99.995%); coating mass test report with every lot; EN 10204 3.1 mill certificate for the base section
Typical Applications
| Industry / Application | Typical use |
|---|---|
| Solar & PV mounting structures | Racking brackets, rail supports and purlin connections where a 25-year design life is expected and the coating weight is set by the local atmosphere. |
| Transmission & distribution structures | Tower details, cross-arm brackets, pole-mounted equipment supports and cable tray brackets exposed to weather year round. |
| Coastal & marine engineering | Jetty details, port equipment brackets, sea-wall fittings and fish-farm frames, where 400 g/m² and heavier coatings are used against salt spray. |
| Road & infrastructure fittings | Guard-rail brackets, sign supports, drainage and kerb details, and small bridge members that will not be painted after erection. |
| Agricultural & greenhouse structures | Greenhouse frames, livestock pen fittings, irrigation supports and machinery brackets in a damp, sometimes ammoniacal environment. |
| Building services & plant supports | External pipe supports, duct brackets, wall brackets and plant-room frames where maintenance access is difficult and repainting is unwelcome. |
| Outdoor furniture & display frames | Shelving, benches, signage frames and display structures where the galvanized finish is left exposed as the final appearance. |
Common Problems Buyers Face — and How We Prevent Them
These are the issues that most often cause claims on steel imports. Each one is controlled in our process before shipment.
White rust (wet-storage stain) on the galvanized surface after a sea voyage
Why it happens: Zinc reacts with moisture when air cannot circulate between bundled members, forming a white surface product that looks like a coating failure on arrival even though it is not.
Our control: Bundles are packed with spacers so air can move between members, shipped dry, and VCI paper is added on long or humid routes. For appearance-critical orders we apply a chromate passivation, which suppresses wet-storage stain.
Coating mass below the specification at isolated points
Why it happens: Uneven dipping time, low bath temperature or localised handling damage can leave thin or bare patches, and a single spot reading can fail receiving inspection.
Our control: Coating mass is measured on a sample basis per lot to GB/T 13912 and reported against the specified minimum average with the individual-reading rule understood, so the material passes inspection rather than being argued about at the port.
Distortion or bow in long slender galvanized angles
Why it happens: The thermal cycle of galvanizing releases residual rolling stress, and light unequal sections in long lengths are the most sensitive to it.
Our control: Heavier thicknesses are selected for slender members, jigging is controlled during dipping and straightness is checked after galvanizing. If a member is distortion-sensitive, tell us at enquiry stage and we will propose a section or a treatment that suits it.
Site welding burns the coating off and leaves bare steel
Why it happens: Galvanizing is applied in the factory but the connection is welded on site, which destroys the coating in the heat-affected zone.
Our control: Punch or drill and cut to length before dipping so no site welding of galvanized members is needed. Where site welding is unavoidable, the weld zone is treated with zinc-rich repair paint, and we can supply the correct touch-up material with the order.
Mixed sizes arrive against a picking list
Why it happens: Adjacent galvanized sizes look alike in a bundle, and the difference is only discovered when the connection will not line up.
Our control: Every bundle is tagged by size, heat number and coating weight, and packed in cutting-list sequence where the order allows. Labels show the section designation in millimetres so a receiving check needs no standard.
Our Supply & Manufacturing Advantages
- Coating specified, not assumed — 30 to 700 g/m² quoted on the enquiry and nominated against the atmosphere the structure will actually stand in.
- Processing before dipping — Cutting, punching and drilling are completed before galvanizing, so hole walls and cut ends are coated and the finished part needs no site rework.
- Asymmetric section plus corrosion protection — The weight saving of an unequal angle combined with a coating that gives decades of maintenance-free outdoor service.
- Coating documentation — Coating mass test report with every lot, plus an EN 10204 3.1 mill certificate for the base section so both the steel and the coating can be verified.
- Standards matched to your project — Coating produced and tested against GB/T 13912, EN ISO 1461, ASTM A123 or JIS H8641 depending on the specification your project references.
- Export packing that protects the coating — Spacers, edge protection and strapping designed for container loading or bulk vessel, so the coating arrives intact rather than scuffed.
Packaging, Delivery & Payment
- Packing: loose in bulk vessel, or bundled and containerised to your requirement. Galvanized and coated products get VCI paper, waterproof wrapping and edge protection. See our export packaging methods.
- Availability: both stock and custom production. Tell us the specification and we will confirm the route.
- MOQ: no strict minimum — one ton can ship.
- Lead time: stock dispatched to port within 3 days; orders needing export packaging about 1 week; custom production quoted per product.
- Payment: stock — 10% deposit, balance before shipment; custom production — 50% deposit, balance before shipment.
- Documents: EN 10204 3.1 mill test certificate with every shipment; third-party inspection (SGS / BV) on request.
Frequently Asked Questions
How heavy a zinc coating should I specify for unequal angle?
As a practical guide: 60 to 100 g/m² for dry indoor service, 180 to 275 g/m² for general outdoor exposure which is the most common export specification, 350 to 500 g/m² for coastal and industrial atmospheres, and 600 to 700 g/m² for severe marine or chemical exposure. The figure quoted is the total on both surfaces. Tell us where the structure will stand and we will nominate the coating weight.
Is the Chinese equivalent of EN S235JR available in galvanized unequal angle?
Yes. Q235B to GB/T 700 is the base grade closest to S235JR and is the grade we galvanize for the European market, referenced in our library as S235-GALV. If your drawing names S235JR we supply the Q235B base and provide the mill certificate with the grade equivalence so your engineer can verify it.
Can the angle be cut and drilled to my drawing before galvanizing?
Yes, and we recommend it. Cutting, punching and drilling before dipping gives a fully coated finished part, whereas working galvanized material afterwards leaves bare steel at every cut and hole. Send the cutting list or fabrication drawing and we will quote the processed, galvanized version.
Does galvanized unequal angle comply with ASTM A123?
Yes. The coating is produced and tested to meet ASTM A123 as well as GB/T 13912 and EN ISO 1461. If your project references ASTM A123 explicitly, say so on the enquiry and the coating inspection and test report will be issued against that standard.
Who supplies galvanized unequal angle steel from China?
We do, from L40×25 to L200×125 with a nominated coating weight, processing to drawing before galvanizing, coating test report and EN 10204 3.1 mill certificate. Send the section list, the coating specification and the destination port and you will receive a quotation with weights, packing and lead time.
Can galvanized angle be welded on site?
It can, but welding damages the coating in and around the weld. The correct approach is to weld before galvanizing wherever possible; where site welding is unavoidable, the weld zone must be cleaned and dressed with zinc-rich repair paint to restore protection. We can supply compatible touch-up material with the order.
What is the minimum order quantity for galvanized unequal angle?
No strict minimum, and one ton can ship. Because galvanizing is a batch process, small quantities of an unusual size are usually grouped into a bath load, so we will confirm the actual lead time rather than promise an immediate dispatch.
How is galvanized unequal angle packed for export?
Bundled with steel straps to container dimensions or loaded loose in a bulk vessel for large tonnage. Spacers are fitted so air can circulate between members and wet-storage stain is avoided, and edge protection is used so the coating is not scuffed during handling.
What is the difference between galvanized and painted angle steel?
Paint is a barrier film that fails at every scratch, cut edge and bolt hole, and it needs periodic inspection and repainting. Galvanizing is a metallurgically bonded zinc coating that protects the steel sacrificially, including at cut edges and drilled holes, so it typically gives decades of maintenance-free service outdoors. Galvanized material costs more per ton but removes the painting, inspection and repainting cost over the life of the structure.
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