Metal drain grating, also known as galvanized drain channel or steel grating for drainage is carefully made of high-quality materials, with a simple yet refined appearance, which can be perfectly integrated into various environmental scenes. From city streets to commercial parks, from residential areas to industrial plants, its versatile style not only ensures drainage function, but also adds a sense of neatness and order to the ground. Each cover is processed with fine craftsmanship, and the edges and corners are rounded and smooth, eliminating safety hazards and escorting pedestrians and vehicles.

The right metal trench drain grating isn't a commodity purchase. The material, load class, slot orientation, open area, and surface treatment must all match the specific conditions of the installation — or the grate fails in service, whether through structural collapse, corrosion, drainage blockage, or safety code non-compliance.

Canri manufactures metal trench drain grating direct from our Hebei factory in galvanized carbon steel, stainless steel (304/316), and cast iron, covering load class A through F per EN1433, with ADA-compliant, heel-proof, and heavy vehicular configurations available. Standard and fully custom sizes supplied to B2B buyers, EPC contractors, and distributors across North America, Europe, the Middle East, Southeast Asia, and Australia.

1) Optimized Draining Design: Water draining area amounts up to 83.3%, which is equal to twice of the cast iron product.

2) Hot-dip Galvanization: Strongly rust-proof, need no maintenance and replacement within 30 years.

3) Anti-theft Design: The cover and the frame are connected with chains, which is anti-theft, safe and easy to open.

4) Saving investment: Cost less than cast iron product in the case of large span and heavy load, and can save expenses incurred by replacement of stolen or crushed cast iron covers.

5) High Strength: Much higher strength and ductility than cast iron and applicable to environments of large span and heavy load such as docks and airports.etc.

6) Various Types: Can meet different environment,load,span and shape requirements, and can be customized based on provided size and shape.

Metal Types for Trench Drain Grating

Choosing the right metal is the most consequential specification decision. Each material performs differently under load, in corrosive environments, and over time. Canri supplies the following metal trench drain grating materials:

Galvanized Steel Trench Drain Grating

Hot-dip galvanized carbon steel is the most widely specified metal trench drain grating material for industrial and commercial applications worldwide. A hot-dip galvanized grate receives a zinc coating of 85μm or greater per ASTM A123, forming a sacrificial barrier that prevents the underlying steel from corroding.

Best for:

• Industrial plant floors, workshop drainage channels, factory wash bays

• Parking garages, commercial parking lots, loading dock drainage

• Roadside drainage, highway runoff channels, municipal street drainage

• Any environment with regular water exposure but no sustained chemical or chloride contact

Advantages: Lowest cost among corrosion-resistant options; decades of proven service life in standard industrial environments (40–50+ years in non-aggressive conditions); high structural strength; available in welded bar grating, press-locked, and solid plate slot styles.

Limitations: Not suitable for sustained exposure to chlorides (road salting, seawater, coastal salt air), strong acids or alkalis, or environments requiring sanitary cleanability (food processing, medical).

Metal Types for Trench Drain Grating

Choosing the right metal is the most consequential specification decision. Each material performs differently under load, in corrosive environments, and over time. Canri supplies the following metal trench drain grating materials:

Galvanized Steel Trench Drain Grating

Hot-dip galvanized carbon steel is the most widely specified metal trench drain grating material for industrial and commercial applications worldwide. A hot-dip galvanized grate receives a zinc coating of 85μm or greater per ASTM A123, forming a sacrificial barrier that prevents the underlying steel from corroding.

Stainless Steel Trench Drain Grating

Stainless steel trench drain grating in grade 304 or 316 is the premium choice for environments where hygiene, chemical resistance, and long-term appearance are non-negotiable requirements.

Cast Iron and Ductile Iron Trench Drain Grating

Cast iron and ductile iron metal trench drain grating provides the highest load capacity available in a drain grate format. These materials are specified for the most demanding vehicular environments where galvanized or stainless steel bar grating cannot sustain the impact and compression loads involved.

Aluminum Trench Drain Grating

Aluminum trench drain grating provides a lightweight, inherently corrosion-resistant option for environments where steel weight is a structural constraint or where non-magnetic, non-sparking properties are required.

Open Area and Hydraulic Drainage Capacity

The open area of a metal trench drain grating — expressed as a percentage of the total grating panel area — directly determines how much water can flow through it per unit of time. A grate with 15% open area will accept significantly less flow than one with 55% open area at the same head pressure.

General open area ranges by grating style:

How to calculate required open area: The total flow capacity of a trench drain system equals: channel cross-section flow rate × open area fraction. If your drainage engineer has specified a required flow rate in GPM or L/s per linear meter, Canri's technical team can calculate the minimum open area required for your trench width and grating style.

Load Class Selection Guide (EN1433 / AASHTO)

Load class is the single most critical specification for metal trench drain grating safety. Undersized grating in a vehicular environment will fail — often catastrophically — when overloaded. Always specify the load class appropriate for the maximum load that will ever cross the grate, not just the typical load.

Canri recommendation: Always apply a dynamic load multiplier. A vehicle in motion generates 25–50% higher effective load than its static weight. A forklift rated at 5,000 kg creates an effective dynamic load of 6,250–7,500 kg when moving. Select the next load class up from the calculated static load for any application with moving vehicles or equipment.

Industrial Plants and Factories

Production floor drainage channels require metal trench drain grating that can handle forklift traffic, chemical splash, and continuous liquid flow from process operations. Hot-dip galvanized welded bar grating (load class D400–E600) is the standard specification. Chemical-resistant stainless steel 316 is specified where acid or caustic exposure is present.

Commercial Kitchens and Food Processing

The hygiene requirements of commercial food preparation eliminate galvanized steel as an option — zinc contamination risk and the inability to deep-clean corroded surfaces make stainless steel trench drain grating mandatory. Grade 304 is the minimum; Grade 316 is specified in facilities using chlorinated sanitizers or with salt brine processes.

Parking Lots and Garages

Surface runoff from parking areas enters the drainage system through metal trench drain grating at low points, ramp transitions, and entry/exit lanes. Galvanized steel (B125–C250 load class) handles standard passenger vehicle traffic. D400 or E600 rated grating is required in truck-accessible areas and commercial vehicle lots.

Roads, Highways, and Municipal Drainage

Road-level trench drains, curb inlets, and linear roadway drainage systems require D400 or E600 class metal trench drain grating (AASHTO H-20 or H-25 equivalent). Cast iron and ductile iron are the standard materials for municipal road drainage grating globally.

Airports and Port Facilities

Aircraft apron drainage, hangar floor channels, and container yard drainage specify the highest load class metal trench drain grating available — Class F900 or AASHTO H-25 — in either heavy ductile iron or welded steel construction to handle aircraft wheel loads and container handling equipment.

Swimming Pools and Aquatic Facilities

Pool surround drainage channels require metal trench drain grating with chloride resistance (Grade 316 stainless), ADA-compliant slot geometry, and smooth surfaces that are safe for bare feet. Stainless steel slotted plate or perforated plate with polished finish is standard.

Commercial Entrances and Architectural Applications

Building entrances, hotel porte-cochères, retail plaza drainage, and architectural drainage features specify metal trench drain grating for both function and aesthetics. Stainless steel slotted plate, anodized aluminum, or powder-coated steel in custom colors and finishes are available for architectural drain specifications.

Car Wash Facilities

High-volume water flow combined with detergent chemical exposure and vehicle traffic makes car wash facilities a demanding environment for metal trench drain grating. Hot-dip galvanized steel with welded bar grating (D400 load class, high open area) is the standard specification for car wash bays.

Why Source Metal Trench Drain Grating from Canri?

Multiple materials and configurations from one factory
Galvanized steel, stainless steel 304/316, and cast iron trench drain grating are all manufactured in-house. One supplier, one quality control standard, one commercial relationship — no need to source drainage grating from multiple vendors for a single project.

Full load class range
Canri produces metal trench drain grating from Class A15 pedestrian grating through Class E600 heavy industrial configurations. The full load class range is available within a single order for projects with mixed-use areas.

Custom dimensions as standard service
Non-standard channel widths, unusual panel lengths, custom slot geometries, and combined frame-with-grating assemblies are standard production capabilities — not special requests requiring additional lead time in most configurations.

Hot-dip galvanizing in-house
Surface treatment is performed in-house, ensuring coating quality control and faster delivery than factories that outsource galvanizing.

ADA and heel-proof configurations available
All required slot width configurations for ADA-compliant and heel-proof specifications are available in both galvanized steel and stainless steel.

Export documentation
EN1433 compliance documentation, material test certificates, mill reports, and full commercial shipping documentation for international buyers.

Specifying metal trench drain grating for an industrial, commercial, or infrastructure project? Send us your channel width, load class, material, and quantity — Canri's technical team will confirm the correct specification and provide a factory-direct quote within 24 hours.