300 to 200 bridges, big and small, big and small, dear! Hello, I'm glad to answer your question. First, one end of the bridge 300 is copied, and then one end of the bridge 200 is made. At this time, make a big head. The big head is one end of the bridge 300 and the small head is one end of the bridge 200. The thickness of the 300ⅹ200mm bridge is 1.5mm, and the thickness of the cover plate is1.3mm. Because the bridge is a product of China enterprises, the industry standard of China is implemented. 400mm to 600mm is the thickness of 2.0. Below 300, such as 100 x 50, thickness 1.2mm, cover plate 1.0. So the 300-wide, 200-state-high and 100-state-high are all 1.5mm thick.