What is Bar Grating?

Bar grating is an open grid assembly of metal bars, in which the bearing bars, running in one direction, are spaced by rigid attachment to cross bars running perpendicular to them or by bent connecting bars extending between them.

Its primary function is to serve as a strong, durable, and slip-resistant surface for flooring, walkways, platforms, and stair treads, while allowing for the passage of air, light, heat, sound, and liquids.

Terminology of Bar Grating

Bearing Bars: These are the main, deep, rectangular bars that carry the load. They span the distance between supports. The height and thickness of the bearing bars determine the grating's load capacity. The main load-bearing direction should be consistent with the direction of the Bearing Bars

Cross Bars: These bars run perpendicular to the bearing bars. Their function is to hold the bearing bars upright and in their correct position. They are typically made from round, square, or twisted square bars.

Banding: A flat bar welded to the ends of a grating panel, flush with the top. It provides a finished edge and helps transfer load between the bearing bars.Span: The distance between the points of support for the grating. Crucially, the bearing bars must be oriented parallel to the span.

Mesh Size: The center-to-center distance between the bearing bars and the cross bars. A common size is 19-W-4, which means bearing bars are spaced 19/16 inches apart, and cross bars are 4 inches apart.

Manufacturing Processes & Types

The method used to join the bearing and cross bars defines the main types of bar grating:

Welded Bar Grating: This is the most common and economical type. Round or square cross bars are fused to the bearing bars at their intersection using high-pressure resistance welding. This creates a strong, one-piece panel.

Press-Locked Grating: Cross bars are inserted into pre-punched notches in the bearing bars. They are then locked into place with immense hydraulic pressure, without any welding. This results in a very clean, crisp appearance, often preferred for architectural applications.

Swage-Locked Grating: Similar to press-locked, but the cross bars (often I-bars or round bars) are inserted into holes in the bearing bars and then deformed (swaged) to lock them in place. This provides excellent lateral stability.

Riveted Grating: This is the oldest manufacturing method. It uses rivets to connect the bearing bars to bent connecting bars. It is exceptionally durable under high-impact, repetitive loads, making it suitable for bridge decks and heavy-duty applications.

Common Materials & Finishes

Bar grating is available in several materials to suit different environments:

Carbon Steel: The most common material due to its strength and low cost. It is typically finished in one of three ways:

Mill Finish (Bare Steel): Uncoated and will rust if exposed to moisture.

Painted: A layer of black or gray paint provides minimal corrosion resistance.

Hot-Dip Galvanized: The most durable finish. The grating is submerged in molten zinc, creating a thick, corrosion-resistant coating for long-term outdoor or industrial use.

Stainless Steel: Used in environments requiring high corrosion resistance and hygienic properties, such as chemical plants, food processing facilities, and marine applications. Common grades are 304 and 316.

Aluminum: Valued for being lightweight, corrosion-resistant, and non-sparking. It's often used in marine environments, wastewater treatment plants, and architectural facades.

Fiberglass (FRP - Fiber Reinforced Plastic): While not metal, FRP grating serves the same purpose. It is non-conductive, highly resistant to chemicals, non-sparking, and lightweight.

Surface Profiles

The top surface of the bearing bars can be either plain or serrated:

Plain Surface: A standard flat surface suitable for most general applications.

Serrated Surface: The top surface of the bearing bars has a series of notches, creating a much more aggressive, slip-resistant surface. This is essential for oily, wet, or icy areas.

Common Applications

Bar grating's versatility makes it ubiquitous across many sectors:

Industrial Plants: Walkways, platforms, safety guards, trench covers, and stair treads in power plants, refineries, and manufacturing facilities.

Wastewater Treatment Plants: Platforms and trench covers that resist corrosion from chemicals and moisture.

Commercial Buildings: Architectural accents, building facades, sunscreens, ventilation grilles, and entrance mats.

Infrastructure: Bridge decking, drainage covers, and platforms for transportation hubs.

Food & Beverage: Stainless steel grating for hygienic and easily cleanable flooring.

Marine & Offshore: Aluminum or galvanized steel grating for ship decks, docks, and offshore oil platforms.

Bar grating is much more than just metal flooring—it is a highly engineered solution designed to provide strength, durability, safety, and versatility in demanding environments. By understanding the different types, materials, and finishes, buyers can select the right product for their specific application.

If you are planning a project that requires reliable and long-lasting flooring or structural support, bar grating remains one of the most trusted solutions worldwide.

Contact Hengchen today at admin@steelbargrating.com for specifications, pricing, and expert guidance on choosing the right bar grating for your needs.