1. Length dimensions of section steels
1.Standard length for railway track is 12.5m or 25m.
2. Dimensions of round steel,wire rod and steel wire are calibrated by the length of their diameter (d) in mm.
3. Dimensions of square steel are calibrated by the length of its edges (a) in mm.
4. Dimensions of hexagonal steel and octagonal steel are calibrated by the distance between their opposite edges (s) in mm.
5. Dimensions of flat steel is calibrated by its width (b) and thickness (d) in mm.
6. Dimensions of I beam and channel beam are calibrated by the waist height (h), the leg width (b), and the waist thickness (d) in mm.
7. Dimensions of equilateral angle iron is calibrated by edge width (b) and thickness (d) in mm. The un-equal angle steel is calibrated by edge width (B, b) and edge thickness (d) in mm.
8. Dimensions of H-shaped steel is calibrated by web plate height (h)，wing plate width (b), web plate thickness (t1), and wing plate thickness (t2) in mm.
2. Length dimensions of plate and strip
1. It is usually calibrated by plate thickness (d) in mm, while strip by strip width (b) and thickness (d) in mm.
2. Each sheet has defined dimensions, for example, for hot rolled steel plate: 1 mm thick plate, there are the following sizes: width 600×length 2000 mm, 650×2000 mm, 700×1420 mm, 750×1500 mm, 900×1800 mm, and 1000×2000 mm, etc.
3. Length dimensions of steel pipe
1. Usually, steel pipe is calibrated by its outer diameter (D), inner diameter, and wall thickness (S) in mm.
2.Each kind of steel pipe has defined dimensions. For example, for seamless steel tubes with an outer diameter of 50 mm, there are 15 different kinds of wall thicknesses ranging from 2.5mm to 10mm; Or, for those with the same wall thickness of 5 mm, there are 29 kinds of outer diameters ranging from 32 mm to 195 mm. Another example: for welded steel pipe with a caliber of 25 mm, there are commercial steel pipe with wall thickness of 3.25 mm, and thickened steel pipe with wall thickness of 4 mm.