Resistance welded grates are referred to as “SP” from the German “Schweißpreß”. The so-called “SP” grids are manufactured according to DIN 24537-1. These grids consist of a support strip and a twisted square – a spreader bar that is pressure welded into the support strips. This design provides a structure at a specific axial spacing, which can be varied according to the production line setup or standard. The most commonly used mesh types for welded grids are 34.3 x 38.1 mm or 34.3 x 22.4 mm and carrier strips 30 x 2 mm, 30 x 3 mm, 40 x 2 mm and 40 x 3 mm. This type of grating can be supplied both unlined and lined. Due to the welding of the contact points, the resulting “net” structure has high strength, the ability to redistribute the load favourably and can withstand not only high but also dynamic loads. Grids of this type have versatile applications, especially in industrial and energy construction.
Pressed grates are referred to as “P” from the German “Preß”. The so-called “P” grates are manufactured according to DIN 24537-1. These grates consist of a support strip and a spreader strip. The latter is pressed by a certain pressure into pre-cut grooves in the carrier strip. The load-bearing elements are thus the load-bearing strips and the spreader strip ensures their structure at a certain axial spacing and partly helps to distribute the load acting on the grating at a given point. “P” grids have a general application in industry and the energy sector, but also in architecture, where they are used as e.g. sun screens on office buildings, as cleaning zones in building entrances, as part of building facades, as soffits, etc. Pressed grids are characterised by a large variation of meshes compared to “SP” grids, where the smallest mesh can be 22.22 x 11.11 mm and the largest mesh 66.66 x 66.66 mm.