Sometimes Perforated Metal is better than Mesh
In most cases for industrial basket construction, Wire Mesh is Cheaper, is Lighter, has More open space, is More durable (mesh flexes where perforated metal will dent on impact) and is Easier to Fabricate into baskets than Perforated Metal. If perforated metal is needed for your engineered basket application, selecting the proper perforated metal size lining is critical in the design.
The two biggest advantages of Perforated Metal over Wire Mesh (for industrial baskets) are that Perforated Metal has a very smooth, flat surface, and that Perforated Metal won’t trap metal chips or turnings like the crossing wires of mesh will.
Perforated Metal is sheet metal with rows of holes punch through. There are unlimited possibilities for the size, shape, and spacing of the punched holes, but the most common commercially available Perforated Metal has round holes, punched in straight rows, with successive rows either in-line or shifted to the side (staggered) to allow the rows to get closer together.
Perforated Metal is designated by four attributes: Hole Size, Hole Spacing, Hole Pattern (Straight or Staggered), and Sheet Thickness:
- Hole Size: This is the diameter of the holes. Every hole is evenly round and exactly this size. The punching operation leaves a small radius on the hole’s edge when the punch enters the sheet metal and a very small burr on the exiting side. We construct our baskets with the “burr side” away from the part space whenever possible. The hole size should be smaller than the smallest part dimension. Obviously, if the are bigger than the parts, the parts will poke thru or fall out.
- Hole Spacing: This is the distance between the nearest adjacent holes, center to centers, in every direction.
- Hole Pattern: In “Straight” perforated metal, the imaginary lines between the centers of four holes form a square. In “Staggered” perforated metal, the imaginary lines between the centers of three holes form a equilateral triangle. Because the holes in staggered perforated metal are closer together and therefore give more “Open Space” than straight perforated metal, we only use staggered perforated metal for our baskets.
- Sheet Thickness: Is the thickness of the sheet metal, in standard sheet metal “gauge” numbers (higher numbers = thinner materials). Perforated metal is available in a range of sheet thicknesses for each hole size and spacing, but as a general rule, the hole diameter is never smaller than the sheet thickness. Most of our Stainless Steel projects use either 16 Gauge (.062″), 18 Gauge (.050″), or 20 Gauge (.037″) perforated metal.
- Open Space Percentage: Open Percentage measures the portion of surface area that is open, not blocked by the metal. The higher the Open Percentage, the better the flow. In general, wire mesh is more open that perforate metal for the same opening size (because the wires between the holes are thinner than the web in perforated metal)
- Weight per Square Foot: Perforated Metal is heavy compared to similar wire mesh. Overall weight of a basket is always a concern for operator safety and comfort. We list it here as a comparison.