There are two methods for manufacturing gratings: machine pressure welding and manual production.
Machine pressure welding uses a high-pressure resistance welding machine. A robotic arm automatically places crossbars onto evenly arranged flat steel bars. Powerful electric welding power and hydraulic pressure then weld the crossbars into the flat steel bars, resulting in high-quality steel gratings with strong welds, high stability, and extremely high strength. This welding process is affected by equipment and current/voltage matching; generally, welding double-bar gratings is stronger than welding single-bar gratings. The welding process is also related to the thickness of the flat steel bars; large width errors can affect welding strength, leading to inconsistent strength. A drawback of this process is the occurrence of false welds and incomplete welds, which can easily cause crossbars to peel off. Due to equipment capacity limitations, this welding process cannot produce heavy-duty steel gratings with large cross-sections. Equipment with a rated capacity below 800KVA can generally only produce flat steel gratings with a thickness of 4mm or less, while equipment with a rated capacity of 1250KVA can generally produce flat steel gratings with a thickness of 5-6mm.
Manually manufactured steel gratings include press-locking, welding, and interlocking weld-free methods. Hand-made welded steel grating involves punching holes or slots in flat steel bars, then inserting crossbars into the holes and spot-welding them. Gaps will exist between the crossbars and the flat steel bars. Each contact point between the crossbars and the flat steel bars is welded, and for closely spaced crossbars, spot welding can be used intermittently. This production process is flexible, allows for product diversification, and can produce virtually a full range of steel gratings, offering advantages in heavy-duty applications. However, because all welding is done manually, it is prone to weak welds, incomplete welds, and false welds, which reduce strength.
Pressure-locked steel grating involves punching holes or slots in flat steel bars, then pressing crossbars onto evenly spaced flat steel bars into pre-made slots. This product is aesthetically pleasing but has lower strength.
Interlocking weld-free steel grating consists entirely of flat steel bars in both directions. Holes or slots are punched in the flat steel bars, then crossbars are inserted into the pre-made slots and locked in place. This product is aesthetically pleasing but also has lower strength.
