Sourcing Electroforged Gratings from India: A Buyer's Guide

Electroforged gratings are one of those products where a 10% saving on the initial purchase is easily lost to a grating that fails load class, corrodes ahead of schedule, or does not fit the existing frame. The product category is also unusually prone to misquotation — 'heavy duty grating' can mean anything from a I-type grating in 65 × 5 mm bearing bar down to a domestic-grade panel in 30 × 3 mm. This guide is written to help you specify the right grating, get an accurate quote, and receive the documentation that protects you when a site inspector or an auditor looks at the installation.

Vajra International manufactures electroforged gratings — also known as forge-welded or press-locked gratings — in Howrah, West Bengal. We supply to mining operations in Australia, petrochemical plants in the Gulf, infrastructure projects across Africa and data centres in the UK and Southeast Asia. What follows is the view from the factory floor.

What electroforged grating actually is — and what it is not

Electroforged grating is made by resistance-welding flat steel bearing bars to cross bars at each intersection point. The weld is produced under pressure with electrical current — hence the name. The result is a monolithic panel where each bearing bar and cross bar is fused, not just crimped or clipped. This matters because the weld is the load path: a properly electroforged panel distributes load across the full panel, not just along individual bearing bars.

It is different from press-locked grating (where cross bars are pressed through slots in bearing bars, no weld) and from riveted or bolted grating (older site-assembled types). For industrial floors, walkways, platforms, trench covers and drain covers carrying real mechanical loads, electroforged is the default because the weld integrity is inspectable and repeatable.

Bearing bar and cross bar — where all the specification lives

The grating specification is defined by two dimensions: the bearing bar (the main load-carrying element, running in the load direction) and the cross bar (the transverse spacing element). These are always stated as height × thickness.

Common bearing bar sizes

• 30 × 3 mm — light-duty, pedestrian access panels. Minimum for industrial applications.
• 40 × 4 mm — light industrial; stair treads, small platforms.
• 40 × 5 mm — medium duty; the most common size for general industrial walkways.
• 50 × 5 mm — medium-heavy duty; standard for petrochemical plant.
• 50 × 6 mm — medium-heavy; offshore and marine platforms.
• 65 × 5 mm — heavy duty; mining, heavy vehicle crossings (pedestrian).
• 65 × 6 mm and 80 × 6 mm — high load; some offshore and mining applications.
• 100 × 10 mm — structural grating for vehicle loads over short spans.

Cross bar pitch and cross bar size

Cross bars run perpendicular to bearing bars. The pitch (centre-to-centre spacing) is typically 50 mm, 60 mm or 100 mm for flat cross bars, or 50/100 for twisted cross bars. The pitch affects the mesh opening size, which matters for drainage and for foot or heel safety (IS 5512 and BS 4592 set minimum opening dimensions for pedestrian gratings). Standard cross bar sizes are 6 × 6 mm for lighter panels up to 10 × 8 mm for heavy-duty applications.

Material and finish — matching the environment

Like most industrial steel products, the correct material and finish choice for gratings comes down to the operating environment. Getting it wrong is expensive because gratings are structural elements — you cannot patch-paint a corroded bearing bar, you replace the panel.

• Mild steel, hot-dip galvanized — the standard for most outdoor and industrial applications. Zinc coating to IS 4759 / ASTM A123 at 65–85 microns covers cut edges and welds. Lasts 20+ years in most industrial environments. The right choice for most projects.
• Mild steel, electro-galvanized — thinner zinc coat (5–15 microns), lower cost. Fine for indoor or sheltered applications. Not suitable for outdoor, coastal, or wet environments.
• Stainless steel 304 — for food and beverage, pharmaceutical, and light chemical plants where cleanability and moderate corrosion resistance are required without the cost of 316.
• Stainless steel 316 / 316L — for offshore, marine, coastal and aggressive chemical environments where chloride-induced pitting is a concern. The right choice for sea water, chlorinated effluent, and acid environments.
• Aluminium — for lightweight requirements. Lower load capacity per kg, but useful where overall structural load is limited or where galvanic corrosion with adjacent aluminium structures is a risk.

If you are specifying for a coastal, offshore or chemical plant, state the environment explicitly and let the manufacturer recommend the right combination — there are cases where 304 suffices where buyers over-specify 316, and cases where a surface treatment beyond HDG is needed.

Load classes and span — the numbers that matter for safety

Grating must be specified to carry the actual load at the actual support span. A panel that is the right size but the wrong bearing bar at the wrong span will deflect beyond the design limit — and in industrial environments, deflection beyond limit means fall protection compliance failure, not just inconvenience.

The two standards that define grating load classes internationally are:

• IS 5512 — the Indian standard for steel grating (floor and walkway). Defines the minimum bearing bar section for each load class (pedestrian, light vehicle, heavy vehicle) and the test method. If you reference one standard when buying from India, reference this.
• BS 4592 (Parts 0–5) — the British and Commonwealth standard for industrial grating. Widely used in the UK, Australia, South Africa and the Gulf. If your project has UK or Australian engineering heritage, this is the reference.
• DIN 24537 — German/European standard; relevant for projects with European EPC contractors.

As a working guide for pedestrian walkway grating at common spans:

• Span 600 mm: 30 × 5 mm bearing bar is typically adequate for pedestrian load.
• Span 1000 mm: 40 × 5 mm bearing bar (pedestrian); 50 × 5 mm for light vehicle near misses.
• Span 1200 mm: 50 × 5 mm bearing bar (pedestrian); 65 × 5 mm where any vehicle could reach the area.
• Span 1500 mm: 65 × 6 mm and above for all pedestrian applications.

Standard panel sizes and custom sizing

Electroforged grating is typically manufactured in standard panels and cut to size. Standard panel dimensions are usually 1000 × 2000 mm or 1000 × 6000 mm depending on the factory. Custom-cut panels — notched for pipes and columns, shaped for curved platforms, with fixed frame holes — are a core part of a manufacturer's capability. If your project has non-rectangular panels, include a sketch or CAD drawing in the enquiry.

Panel-to-panel connecting angles, hold-down clips, and nosings for stair treads are typically quoted separately. If your project requires them, list them as a separate BOM item in your enquiry.

How to write an enquiry that gets a useful quote

Grating quotation is fast when the enquiry is complete. The key information:

1. 1Bearing bar size: height × thickness (e.g. 50 × 5 mm) and material (MS HDG / SS 304 / SS 316)
2. 2Cross bar size and pitch (e.g. 6 × 6 mm cross bar at 50 mm pitch)
3. 3Standard: IS 5512, BS 4592, DIN 24537 — state which and the load class if known
4. 4Panel dimensions: width × length. If custom shapes, attach a sketch.
5. 5Finish: hot-dip galvanized (IS 4759 / ASTM A123), electro-galvanized, bare (for SS), paint
6. 6Surface option: plain, serrated (anti-slip), galvanized serrated
7. 7Quantity: number of panels by type, or area in m²
8. 8Accessories: connecting angles, hold-down clips, stair tread nosings — list them
9. 9Destination port and Incoterm (FOB, CIF or CFR)
10. 10Support span — clear distance between supports, for load class confirmation

Indicative pricing FOB India

Grating is priced by weight (per tonne or per m²) and the cost scales with bearing bar size. As a budgeting guide, hot-dip galvanized mild-steel electroforged grating FOB India:

• 30 × 5 mm bearing bar, plain: roughly USD 800–1,100/tonne (approx USD 25–35/m² at standard grid)
• 40 × 5 mm bearing bar, plain: roughly USD 750–1,000/tonne (approx USD 30–42/m²)
• 50 × 5 mm bearing bar, plain: roughly USD 700–950/tonne (approx USD 42–58/m²)
• 65 × 5 mm bearing bar, plain: roughly USD 680–900/tonne (approx USD 65–85/m²)
• SS 304 panels: typically 3–4× the mild-steel HDG price for comparable dimensions

Serrated panels add 5–10% to the plain panel price. Custom cutting adds a fixed tooling charge per shape, which becomes negligible on volume orders but significant on small quantities of many different shapes.

Documentation: what to require

• Mill Test Certificate (MTC) — for the base steel, confirming grade (e.g. IS 2062 Grade A for structural quality) and heat number. Required for projects with QA requirements.
• Hot-dip galvanizing certificate — confirming the coating standard (IS 4759 / ASTM A123) and average and minimum zinc thickness measured on the lot.
• Inspection report — dimensional check: panel size, bearing bar height and thickness, cross bar pitch. For critical structural applications, arrange third-party inspection (SGS, BV, Intertek) before shipment.
• Certificate of Origin (COO) — for duty preference. India's trade agreements cover steel gratings under HS 7308 (structures) or 7326 (articles of iron or steel, NEC). A COO reduces duty to zero or near-zero for UAE buyers under India–UAE CEPA.
• Packing list and commercial invoice with HS code — state the HS code explicitly and agree it with your customs broker before shipment to ensure the right duty rate.

Mistakes that lead to replacements

• Specifying panel size without specifying bearing bar — the single most common and most expensive error. Results in under-strength panels that have to be replaced.
• Using pre-galvanized (electro-galvanized) grating outdoors — bare edges at cut and weld points corrode rapidly. Use hot-dip galvanized for any outdoor, humid or wet application.
• Ordering custom-shaped panels without a drawing — approximate verbal descriptions produce panels that do not fit. Provide a dimensioned sketch for any non-rectangular cut.
• Forgetting connecting hardware — the grating arrives, but there are no hold-down clips or connecting angles. A second small shipment for accessories costs more in freight than the hardware.
• Specifying span as panel length rather than clear span — deflection tables use clear span (between supports). A 1200 mm panel on 1000 mm centres is a 1000 mm span, not a 1200 mm span.

How to tell a manufacturer from a trader

Electroforged grating requires a specific welding line — an electroforging press that applies simultaneous pressure and current across all bearing bar and cross bar intersections in one pass. It is not something a general fabricator can produce. A manufacturer runs and maintains this line; a trader buys from a manufacturer and resells.

• Ask for the production process description — electroforging, not manual welding or press-locking.
• Ask for a sample MTC and galvanizing certificate from the last lot, before ordering.
• Ask for the electroforging capacity per day — a manufacturer knows it; a trader does not.
• Ask about custom cutting — a manufacturer with their own equipment will quote custom shapes easily; a trader quotes them because they sub-contract.

Vajra International manufactures electroforged steel gratings in Howrah under ISO 9001:2015, producing standard and custom panels in mild steel (HDG), stainless steel 304 and 316. We supply to mining sites in Australia, petrochemical plants across the Gulf and Africa, and infrastructure projects in 30+ countries.