Modern steel components are welded or bolted together. The basic structure is welded chromoly steel tubing. The hull is welded steel, with a cast steel turret. The knives were then welded onto an existing steel frame. Until relatively recently, structural steel connections were either welded or riveted. These were welded together using specially designed high-strength steel, and then fitted out. The weapon carriage is lightweight welded aluminum, mounted on a variable recoil mechanism. Generally, HY-80 is welded with an AWS ER100S-1 welding wire. For this reason, typically galvanized steel is not welded, or the zinc is removed first. The hull was welded not riveted. After this, 237-metre long steel trusses were welded to the gates. The hull is welded steel, and the vehicle is amphibious. High strength steels for prestressed concrete cannot be welded. Seams of tubes can be welded this way. Silver solder is also used in manufacturing to join metal parts that cannot be welded.