How to Choose the Right Expanded Metal Mesh Size for Your Baskets

Expanded metal baskets can be a great alternative to using sheet metal or custom wire baskets in many situations. Baskets made with expanded metal offer the better durability and tensile strength than steel wire while having better drainage and air flow than sheet metal baskets. This makes expanded metal baskets almost perfect for heavy-duty parts washing processes where thin custom wire baskets wouldn’t cut it, but sheet metal would interfere too much with parts finishing processes.

However, not all expanded metal baskets are the same. When building an expanded metal basket, it’s important to carefully consider the size of the mesh—i.e. how much open space there is between solid surfaces (also known as strands) in the expanded metal sheet and the size/thickness of those surfaces.

If the expanded metal mesh size is too tight, it might interfere with wash processes or allow water (or other chemicals and process runoff) to collect in the basket. Too open, and parts may fall through or the basket might be too weak.

So, how can you pick the right expanded metal mesh sizes for your custom parts washing baskets? Here is a quick guide:

The Factors Behind Your Mesh Size Choices

When creating a sheet of expanded metal mesh, the manufacturer will need to consider the:

• Weight of Held Parts. Naturally, the weight the basket will be designed to hold plays a factor in how wide the space between strands can be, as well as how thick each strand needs to be. The heavier the expected load, the thicker the strands of the expanded metal mesh will need to be.
• Type of Metal Used for the Mesh. The type of metal used in the expanded metal mesh also plays a role in determining how thick or thin the strands can be and how much open space there can be between strands. For example, 304 stainless steel is sturdier than aluminum at the same sizes, so 304 SS can be made thinner and wider for the same weight tolerances. High-carbon steels are even stronger, so carbon steel expanded metal mesh can take even more weight than 304 SS mesh of the same size.
• Needs of the Wash Process. The wash process itself will heavily influence the design of a custom expanded metal mesh basket, right down to the spacing of the mesh. Many aqueous wash processes require a lot of open space to facilitate water/air flow and keep runoff from collecting in the basket (this is why custom wire baskets are usually the first option for these processes). So, for water- or chemical-based wash processes, thinner mesh with more open space is usually the go-to option. Additionally, the chemicals and temperatures used in the wash process may influence the material choice.

Some Examples of Different Mesh Size and Material Choices

Special thanks to Alro Steel for the following examples of metal mesh sizes for stainless steel, aluminum, and carbon steel:

As you can see, the carbon steel example, though possessing the thinnest strands, had the highest weight capacity of all the expanded metals in the Alro Steel list. This may have been bolstered somewhat by the fact that it had the least open space, but the difference is still significant.

304 stainless steel serves as a great “all-round” option, with its ability to resist chemical attack/oxidation and moderately high tensile strength—being able to take nearly twice the weight of the aluminum expanded metal example. In most cases, the stainless steel would be the better option, unless the chemicals in the wash process were severe enough to corrode it but would not affect aluminum.

Some manufacturers may even choose to use a specialized polymer coating to protect their expanded metal baskets from corrosives so they can use stronger metals while prolonging the useful life of the basket.

Need help finding the perfect expanded metal basket for your heavy-duty parts washing and handling needs? Reach out to the experts at Marlin Steel for help and advice today!