The length dimension of steel is the most basic dimension of all kinds of steel, which refers to the length, width, height, diameter, radius, inner diameter, outer diameter and wall thickness of steel.
The legal units of measurement for the length of steel are meters (m), centimeters (cm), and millimeters (mm). In current habit, there are also useful inches
indicated, but it is not a legal unit of measurement.
1. The scope and length of steel is an effective measure to save materials. The fixed scale is the length or the length times the width is not less than a certain size, or the length. Delivery within the size range of length by width. The production unit can produce and supply according to this size requirement.
2. Indefinite length (usual length) Any product size (length or width) that is within the scope of the standard and does not require a fixed size is called indefinite length. The indeterminate length is also called the usual length (through length). Metal materials delivered to indefinite lengths can be delivered as long as they are within the specified length. For example, ordinary round bars not larger than 25mm, whose length is usually specified as 4-10m, can be delivered with lengths within this range.
3. The fixed-length cut into a fixed size according to the order requirements is called the fixed-length. When the delivery is made in fixed length, the delivered metal material must have the length specified by the buyer in the order contract. For example, if it is stated in the contract that the delivery is based on a fixed length of 5m, the delivered materials must be all 5m long, and those shorter than 5m or longer than 5m are unqualified. But in fact, the delivery cannot be all 5m long, so it is stipulated that positive deviations are allowed, but negative deviations are not allowed.
4. The double ruler is cut into grid multiples according to the fixed ruler required by the order, which is called the double ruler. When delivering according to the length of multiple rulers, the length of the delivered metal material must be an integral multiple of the length (called a single ruler) specified by the purchaser in the order contract (plus a saw). For example, if the purchaser requires the length of a single ruler in the order contract to be 2m, then the length is 4m when it is cut into a double ruler, and it is 6m when it is cut into a triple ruler, and one or two drill holes are added respectively. . The amount of kerf is specified in the standard. When the double ruler is delivered, only positive deviation is allowed, and negative deviation is not allowed.
5. The length of the short ruler is less than the lower limit of the indefinite length stipulated by the standard, but not less than the shortest length allowed. For example, the water and gas transmission steel pipe standard stipulates that 10% (calculated by the number) of short-length steel pipes with a length of 2-4m are allowed in each batch. 4m is the lower limit of the indefinite length, and the shortest allowable length is 2m.
6. The width of the narrow ruler is less than the lower limit of the indeterminate width specified by the standard, but not less than the narrowest allowed width is called a narrow ruler. When delivering by narrow feet, attention must be paid to the narrow feet ratio and the narrowest feet stipulated by the relevant standards.
Post time: Jul-13-2022