The answer to whether tinned steel coil or galvanized steel coil is more corrosion-resistant is not absolute. It depends on whether the coating is intact or damaged.

With intact coating: Galvanized steel coil is very corrosion-resistant; tinned steel coil is extremely corrosion-resistant and has a bright, stable finish, making it practically food-grade safe.

With damaged coating: In galvanized steel coil, the reactive zinc will corrode preferentially, protecting the steel and making it more corrosion-resistant; in tinned steel coil, the steel at the damaged area will corrode faster than before plating, posing a very high risk of corrosion.

Coiled rebar is a type of rebar, referring to ribbed steel bars with spiral transverse ribs on their surface. It also refers to rebar coiled together like a wire rod. Coiled rebar is generally thread-shaped, with diameters of 6.5mm, 8.0mm, 10mm, 12mm, and 14mm, etc. While rebar only comes in diameters of 9-12mm, coiled rebar can be cut to any desired size.

Rebar is hot-rolled ribbed steel bar, mainly used as the framework for reinforced concrete building components. It requires certain mechanical strength, bending deformation performance, and weldability. The raw material for producing rebar is carbon structural steel or low-alloy structural steel that has undergone refining and smelting. The finished rebar is delivered in hot-rolled, normalized, or hot-rolled condition. It is generally in straight bar form.

Wire rod is the type of hot-rolled steel with the smallest cross-sectional area. Wire rod is delivered in coils, hence the name "coiled bar." Wire rod is generally round, with diameters typically ranging from 5 to 9mm.

Rebar mesh is a robust reinforcing mesh structure formed by welded links of rebars. Common mesh sizes include: Type A: 20mm*20mm, Type B: 10mm*20mm, Type C: 15mm*20mm, Type D: 10mm*10mm, Type E: 15mm*15mm, and Type F: 10mm*15mm. The diameter of the rebar mesh is typically 4-14mm. The maximum width is 2.4 meters, and the maximum length is 12 meters.
The calculation formula is: Weight of rebar = Length of rebar * Specific gravity of rebar. Therefore, reinforcing mesh can be used to calculate the weight of rebars. The total length of rebars with different diameters multiplied by their respective specific gravity gives the total weight of the rebars, which is actually the theoretical weight.