Punched / Perforated Angle Steel (Universal Angle) | Slotted & Drilled
Hot-dip galvanized angle steel punched with a standard regular slotted hole pattern and sold as a bolt-together framing system. Sizes L25 to L63 with 2 to 5 mm leg thickness, single-face or double-face punching, supplied in 6 m, 9 m and 12 m lengths or cut to your drawing.
Product Overview
Punched angle steel — also called perforated angle, slotted angle or, in Chinese trade usage, universal angle — is a standard equal angle that has been precision punched with a regular pattern of elongated slots along the leg before it is hot-dip galvanized. Because the holes are already there, a frame can be assembled on site with bolts and a spanner instead of being drilled, welded and repainted.
The slot pattern is the functional difference between this and plain angle. The elongated slots give a little adjustment in the direction of the leg, so a connection can be aligned even when the structure or the equipment it supports is not perfectly square, and shelf heights or rail positions can be changed later without new holes. A set of punched angles can therefore be reconfigured as requirements change rather than being cut up and scrapped.
Stock covers L25, L30, L40, L50 and L63 with leg thicknesses from 2 mm to 5 mm, punched on one face or both faces and galvanized after punching so the slot walls are coated. Material is Q235B base steel with a hot-dip zinc coating to GB/T 13912 / EN ISO 1461, and custom hole patterns can be produced to drawing for volume orders.
Specifications & Size Range
Standard slotted angle range. Slot pitch and slot size can be produced to your pattern for volume orders; single-face and double-face punching are both available. Mill lengths are 6 m, 9 m and 12 m, and cut-to-length service is available.
| Section size (mm) | Leg thickness (mm) | Punching | Coating | Typical load duty |
|---|---|---|---|---|
| L25×25 | 2 / 3 | Single or double face | Hot-dip galvanized | Light shelving, display frames, cable supports |
| L30×30 | 2.5 / 3 / 4 | Single or double face | Hot-dip galvanized | Light and medium shelving, greenhouse frames, guards |
| L40×40 | 3 / 4 / 5 | Single or double face | Hot-dip galvanized | Medium racking, work benches, equipment frames |
| L50×50 | 4 / 5 | Single or double face | Hot-dip galvanized | Heavy storage racks, solar racking, plant supports |
| L63×63 | 5 | Single or double face | Hot-dip galvanized | Heavy multi-tier racks, structural framing systems |
Tolerances
Hole position, slot length and slot pitch tolerance are confirmed against the sample or drawing approved before production. Base section dimensions and straightness follow GB/T 706, and the zinc coating follows GB/T 13912 / EN ISO 1461 with a coating mass test report issued per lot. Coating is measured after punching, so measurements are taken on the leg face away from the slots.
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 | A36 / A283 Gr.C | S235JR (EN 10025-2) | SS400 (JIS G3101) | St37-2 | Carbon structural steel (GB/T 700) |
| Q235B + hot-dip galvanized | A123 / A153 (ASTM) | EN ISO 1461 | JIS H8641 | DIN 50976 | Hot-dip galvanized structural steel (GB/T 13912) |
Grade Notes
- Q235B — The workhorse structural grade in China. Fully weldable, excellent cost-performance, the closest Chinese equivalent to ASTM A36 / EN S235JR.
- Q235B + hot-dip galvanized — Zinc coating of 30–700 g/m² gives 5–30+ years of atmospheric corrosion protection depending on thickness and environment.
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 | ≥235 MPa | — | 370–500 MPa | ≥26% | +20 °C, ≥27 J | — |
| Q235B + hot-dip galvanized | — | — | — | — | — | Coating 30–700 g/m² (both sides), made to order Adhesion per GB/T 13912 bend test |
Standards & Documents
- GB/T 706 — hot-rolled equal angle (base section dimensions and tolerance)
- GB/T 700 — carbon structural steels (Q235B base material)
- GB/T 13912 — hot-dip galvanized coatings on fabricated steel articles
- EN ISO 1461 / ISO 1461 — hot-dip galvanized coatings (international equivalent)
- ASTM A123 — zinc (hot-dip galvanized) coatings on iron and steel products, on request
- Coating mass test report and EN 10204 3.1 mill certificate with every lot; hole pattern to approved sample
Typical Applications
| Industry / Application | Typical use |
|---|---|
| Warehouse & storage racking | Multi-tier shelving, material dividers, carton-flow and light pallet racks, where shelf levels can be re-set without new drilling. |
| Solar & PV mounting frames | Ground-mount and rooftop bracket frames where the slots take up tolerance between rails and posts and the galvanized coating handles outdoor service. |
| Electrical & communications supports | Meter-box frames, distribution board supports, cable tray brackets and equipment bases, with the slots allowing alignment of prefabricated components. |
| Equipment & machinery frames | Machine bases, conveyor supports, pipe and duct supports and non-standard equipment mounting frames assembled from stock material. |
| Greenhouse & agricultural structures | Greenhouse frames, pen dividers, irrigation supports and shade structures in a damp or mildly corrosive environment. |
| Shopfitting & display frames | Retail display units, shelving, signage frames and exhibition stands where the bright galvanized finish is the finished appearance. |
| Walkways, guards & safety frames | Handrail infill frames, machine guards, walkway edging and temporary protective framing that must be dismantled and reused. |
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.
Bolted frames will not line up because the hole pitch is not consistent
Why it happens: Punching with worn tooling or uncalibrated feed produces a drifting pitch, and the error accumulates over a long run of slots so a pre-fabricated frame no longer fits.
Our control: Tooling is checked before each production run, pitch is verified against the approved sample at the start and during the run, and a first-article inspection record is issued before the balance of the order is punched.
Bare steel or thin coating inside the slots
Why it happens: Angle punched after galvanizing has sheared edges and hole walls with no coating at all, which is where corrosion starts.
Our control: All punching is carried out before galvanizing, so the slot walls and cut edges are coated with the same zinc layer as the leg faces. Galvanized-then-punched material is never shipped as standard.
The section is too light for the rack that was built on it
Why it happens: Light punched angle with a 2 mm leg looks adequate in a catalogue but deflects visibly under a heavy multi-tier load, and the frame becomes unstable.
Our control: Tell us the shelf span and the load per level and we will nominate the section and leg thickness from the bending capacity rather than from appearance. For heavy storage bays we recommend L50×50 or L63×63 with a 5 mm leg.
White rust forming between bundled members in transit
Why it happens: Zinc reacts with trapped moisture when air cannot circulate inside a tight bundle, producing a white surface stain that looks like a defect on arrival.
Our control: Bundles are packed with spacers and shipped dry, with VCI paper on long or humid routes, and chromate passivation is available for appearance-critical orders. A light white film does not reduce the coating life and can be washed off.
The standard slot pattern does not suit the components being mounted
Why it happens: A standard pattern is fine for general racking but will not take a specific bracket, clamp or equipment foot without an adapter.
Our control: Send the mating component drawing with the hole centres and diameters and we will quote a custom punching pattern for volume orders, including slot length, pitch, edge distance and the number of punched faces.
Our Supply & Manufacturing Advantages
- Assembly without drilling or welding — Slotted holes let a frame be bolted together on site with hand tools, which removes the need for drilling equipment, welding sets and repainting.
- Adjustable and re-usable — The elongated slots allow alignment on uneven ground and let shelf heights or rail positions be changed later without cutting new material.
- Coated after punching — Punching is completed before hot-dip galvanizing, so slot walls, cut ends and edges all carry the same zinc coating as the leg faces.
- One stock item, many structures — A single section can become racking, a support frame or a guard frame, which reduces the number of different profiles you have to hold.
- Coating weight nominated to the site — Standard export coating for general outdoor service, or a heavier coating for coastal and high-humidity sites, with a coating test report per lot.
- Custom patterns and cut lengths — Custom slot pitch, slot size and multi-face punching are available for volume orders, and material can be delivered pre-cut to your cutting list.
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
What is punched (universal) angle steel used for?
It is a bolt-together framing material used for warehouse shelving and racking, solar mounting frames, electrical and equipment supports, machine bases, greenhouse frames and shopfitting displays. Its advantage is that a frame can be assembled, adjusted and later dismantled with hand tools instead of being welded.
Is punched angle steel galvanized?
Yes. Standard production is hot-dip galvanized after punching to GB/T 13912 or EN ISO 1461, so the slot walls and cut ends are coated as well as the leg faces. The coating weight is nominated on the enquiry, typically 180 to 275 g/m² for general outdoor service and heavier for coastal sites.
Can you produce a custom slot pattern?
Yes, for volume orders. Send the drawing of the component that will bolt to the angle, with hole centres, slot length, slot width and edge distances, and we will produce a sample for approval before the full run is punched. Standard patterns are also available if you have no fixed requirement.
What is the difference between punched angle steel and plain galvanized angle?
Plain galvanized angle has no holes and must be drilled, punched or welded at the point of use. Punched angle arrives with a regular slot pattern already formed and galvanized, so frames can be bolted together directly and later adjusted. If the structure is welded and its geometry will never change, plain angle is cheaper; if it is bolted, adjustable or likely to be re-used, punched angle wins.
Who supplies punched angle steel from China for export?
We supply slotted and perforated angle from L25 to L63 in 2 to 5 mm leg thickness, galvanized after punching, with a coating test report, EN 10204 3.1 mill certificate for the base section and cut-to-length service. Send the section, the hole pattern or the intended use and we will quote the finished part.
What size punched angle should I use for a warehouse shelf?
For light shelving up to about 500 mm span use L30×30 or L40×40; for medium racks with longer spans use L40×40 with a 4 to 5 mm leg; and for heavy multi-tier storage bays use L50×50 or L63×63. Give us the shelf span and the load per level and we will confirm the section from its bending capacity.
How is the material packed and what is the lead time?
Bundles are strapped to container dimensions with spacers between members, VCI paper on long or humid routes, and edge protection to preserve the coating. Common sizes are dispatched to the port within 3 days; custom punching patterns and special cut lengths take about one to two weeks.
Do you have a minimum order quantity for custom punched angle?
For standard patterns there is no strict minimum and one ton can ship. For a custom slot pattern there is a practical set-up cost in the punching tooling, so a custom pattern is normally quoted from a few tons upward, and we will tell you the break point honestly.
What documents are supplied with a punched angle order?
An EN 10204 3.1 mill test certificate for the base steel, a coating mass test report to GB/T 13912 or EN ISO 1461, a first-article inspection record for the hole pattern, plus the commercial invoice, packing list, bill of lading and certificate of origin.
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