1、 Steel length dimensions
The length dimension of steel is the most basic dimension of various types of steel, referring to the length, width, height, diameter, radius, inner diameter, outer diameter, and wall thickness of the steel. The legal units of measurement for steel length are meters (m), centimeters (cm), and millimeters (mm). In current customs, inches are also used to represent, but they are not legal units of measurement.
1. The range sizing of steel is an effective measure to save materials. Range sizing refers to the delivery of goods within a certain size range of length or length multiplied by width, or from what to what. The production unit can produce and supply according to this size requirement.
steels
2. Uncertain length (usually length): Any product size (length or width) that falls within the specified range of standards and does not require a fixed size is called an indefinite length. The indefinite length is also known as the usual length (through length). metal materials delivered to varying lengths can be delivered within the specified length range. For example, if a regular round steel with a length of no more than 25mm is usually specified as 4-10m, then round steel with a length within this range can be delivered.
3. Fixed length refers to cutting into fixed dimensions according to the order requirements. When delivering according to the specified length, the delivered metal material must have the length specified by the purchaser in the order contract. For example, if the contract specifies delivery with a fixed length of 5m, the delivered materials must all be 5m long, and those shorter than 5m or longer than 5m are considered unqualified. However, in reality, delivery cannot all be 5m long, so it is stipulated that positive deviation is allowed and negative deviation is not allowed.
4. A multiple ruler is called a multiple ruler if it is cut into integer multiples according to the fixed size required by the order. When delivering according to a multiple length, the length of the metal material delivered must be an integer multiple of the length specified by the purchaser in the order contract (called a single length) (with a saw cut added). For example, if the purchaser requires a single length of 2 meters in the order contract, the length is 4 meters when cutting into double lengths and 6 meters when cutting into three lengths, and one or two saw cuts are added separately. The cutting amount is specified in the standard.
When delivering multiple measurements, only positive deviations are allowed, and negative deviations are not allowed.
5. A short ruler is called a short ruler if its length is less than the lower limit of the indefinite length specified in the standard, but not less than the allowed shortest length. For example, according to the standards for water and gas transportation steel pipes, 10% (calculated by number) of 2-4m long short steel pipes are allowed in each batch. 4m is the lower limit of the indefinite length, and the shortest allowed length is 2m.
6. A narrow ruler is defined as one whose width is less than the lower limit of the adjustable width specified in the standard, but not less than the allowable narrowest width.
When delivering according to narrow ruler, attention must be paid to the narrow ruler ratio and the narrowest ruler specified in relevant standards.
2、 Example of steel length dimensions
1. Length dimension of section steel
There are two standard lengths of train tracks: 12.5m and 25m The dimensions of round steel, wire rod, and steel wire are calibrated in millimeters (mm) of diameter d The size of square steel is calibrated in millimeters (mm) of side length a The dimensions of hexagonal and octagonal steel are calibrated in millimeters (mm) of the distance s from the opposite side The size of flat steel is calibrated in millimeters (mm) of width b and thickness d The dimensions of I-beams and channel steels are calibrated in millimeters (mm) of waist height h, leg width b, and waist thickness d The size of equilateral angle steel is calibrated in millimeters (mm) of equal edge width b and edge thickness d. The dimensions of unequal edge angle steel are calibrated in millimeters (mm) of edge width B, b, and edge thickness d The dimensions of H-shaped steel are calibrated in millimeters (mm) based on the height h of the web, the width b of the wing, the thickness t1 of the web, and the thickness t2 of the wing.
2. Length dimensions of steel plates and strips
Generally, it is calibrated in millimeters (mm) of the thickness d of the steel plate. The steel strip is calibrated in millimeters (mm) based on its width b and thickness d Single steel plates have specified different sizes, such as hot-rolled steel plates with a thickness of 1mm and a width of 600 × Length 2000 mm; six hundred and fifty × 2000 mm; seven hundred × 1420 mm; seven hundred and fifty × 1500 mm; nine hundred × 1800 mm; one thousand × 2000 mm, etc.
3. Length dimensions of steel pipes
Generally, the outer diameter D, inner diameter, and wall thickness S of the steel pipe are calibrated in millimeters (mm) Each type of steel pipe has a specified different size, such as 15 types of seamless steel pipes with an outer diameter of 50mm and a wall thickness of 2.5-10mm; Alternatively, there are 29 types with the same wall thickness of 5mm and an outer diameter of 32-195mm. For example, welded steel pipes with a nominal diameter of 25mm have a wall thickness of 3.25mm for ordinary steel pipes and 4mm for thickened steel pipes.
3、 Steel weight
1. Theoretical weight of steel
The theoretical weight of steel is calculated based on its nominal size and density (formerly known as specific gravity), which is called the theoretical weight. This is directly related to the length, cross-sectional area, and allowable deviation of the steel. Due to the allowable deviation of steel during the manufacturing process, there is a certain discrepancy between the theoretical weight calculated using the formula and the actual weight, so it is only used as a reference for estimation.
2. Actual weight of steel
The actual weight of steel refers to the weight obtained by actual weighing (weighing) of steel, which is called the actual weight. The actual weight is more accurate than the theoretical weight. 3. Calculation method for steel weight
(1) Gross weight is the symmetry of "net weight", which is the total weight of the steel itself and packaging materials. Transportation companies calculate freight based on gross weight. But in the purchase and sale of steel, it is calculated based on net weight The net weight is the symmetry of the 'gross weight'. The weight of steel minus the weight of packaging materials is the actual weight, which is called the net weight. In the purchase and sale of steel, it is generally calculated based on net weight The weight of steel packaging materials is called the tare weight The weight unit used in calculating shipping costs based on the gross weight of steel. Its legal unit of measurement is tons (1000kg), as well as long tons (1016.16kg in English weight units) and short tons (907.18kg in American weight units) Billable weight is also known as "billable ton" or "freight ton". The weight of steel charged by the transportation department for shipping. Different transportation methods have different calculation standards and methods. For railway vehicle transportation, the marked load of the used truck is generally used as the billing weight. Highway transportation charges freight based on the deadweight tonnage of the vehicle. The minimum chargeable weight for less-than-truckload vehicles on railways and highways is based on a gross weight of several kilograms. If it is not sufficient, it will be rounded up.
4、 Theoretical weight calculation of steel
The unit of measurement for calculating the theoretical weight of steel is the kilogram (kg). The basic formula is: W (weight, kg)=F (cross-sectional area mm2) × L (length, m) ×ρ (Density, g/cm3) × 1/1000, the density of steel is 7.85g/cm3
