Metal Grate Material: Best Type for Strength, Durability Cost?

Metal grating is used wherever a durable, long-lasting and cost-effective industrial flooring is needed. But much like most metal products, there are hundreds of variations when considering material type, bar thickness, and bar spacing.

In this article, we’ll go through some of the options for metal grating, what to consider when buying, and how to choose the best option for your project.

Common Metal Grate Materials and How They Differ

Floor grating is commonly available in mild steel, stainless steel, and aluminum. Most commonly, mild steel grating will be galvanized before being installed to protect it from corrosion.

The most commonly used types of grating are safety grating and bar grating. Safety grating typically uses pressed or expanded steel sheets to give a surface with plenty of grip in wet conditions.

Bar grating flooring is constructed of flat and round bars, with the flats being welded on edge for strength. It can therefore be used to span gaps between structural members, rather than just to cover an existing floor or landing.

This means the material’s strength, as well as ease of use, is an important factor when selecting a product.

• Mild Steel is likely to be the cheapest option, and relatively easy to cut and weld, but may require galvanizing after fabrication
• Stainless steel generally needs no coating, and is just as easy to connect to and fabricate, but typically costs much more
• Aluminum grating is lightweight but expensive

Strength, Load Ratings, and Performance by Material

Each size and thickness of metal grating, also known as open grid flooring, has a load and span rating. This is because it is used not only to cover a floor area but to provide structural support for any loads applied.

Span distances are affected by the thickness and depth of the supporting bars, as well as the material used. Some of the heavy-duty section sizes can be installed with spans of up to 1.5m between supporting members.

Factors that affect load ratings:

• Material
• Bar spacing
• Load bar thickness and width
• Span between supporting members

Corrosion Resistance and Environmental Suitability

When it comes to corrosion resistance, stainless steel will always be the best option, but it does come at a cost. Galvanized steel is cost-effective and great for resisting corrosion.

Aluminum flooring is readily available but is also expensive and isn’t generally as strong, necessitating more structural support, though it is useful in applications where weight is a factor.

In many applications, galvanized mild steel grating is acceptable, and exceptions can include parts that are likely to spend any amount of time submerged in seawater or in certain acidic environments.

Cost, Maintenance, and Lifespan Considerations

With how cheap and readily available mild steel grating is, it is often the best choice, with stainless steel only being selected in extreme circumstances. Be sure to consider the long-term cost implications, though.

However, galvanized mild steel can still rust, and not only that, if the parts require welding, galvanizing after fabrication is the best option, adding cost to consider.

For the longest lifespan in harsh conditions, stainless steel is the best choice.

How to Choose the Right Metal Grate Material for Your Project

To find the correct grate type and material, consider the following:

Structural support and design

If the flooring needs to support the load of people walking on it, then bar grating is best, as it can span gaps of up to 1.5 meters, depending on the thickness and width of the bars used

Corrosion and cost

If being submerged in water or in a highly corrosive environment, stainless steel is likely to be worth the extra cost; if not, galvanized mild steel is likely sufficient.

Also consider the cost implications of having to buy self-coloured grating and galvanizing afterwards if lots of fabricating and welding are needed, as cut or welded areas of pre-galvanized flooring will no longer be protected from corrosion.

Span and Load

Metal grating comes in differing bar thicknesses and widths to suit larger loads or bigger spans. Cross-reference load tables with your design and requirements.

In some cases, it’s better to use a lighter grating type and more supporting members, but this can increase the overall weight of the structure.

Find Your Metal Grating at Metal Supermarkets

Whether you need a small piece for a step or repair or a large quantity for a big project, Metal Supermarkets has a wide range in stock. Find your nearest store, or browse the selection of grating available.