1. Indefinite length (usually length)
The length of galvanized seamless pipes is generally different in length, which is called indefinite length within the range specified by the standard. Indeterminate length is also called normal length (pass length). For example, 159*4.5 galvanized seamless pipe usually has a length of 8 to 12.5
Cut to a fixed size according to the order requirements is called cut length. When delivering according to the fixed length, the delivered galvanized seamless pipe must have the length stated in the order contract by the purchaser. For example, if it is specified in the contract that delivery is to be made at a length of 6m, the delivered materials must be 6m long, and those shorter than 6m or longer than 6m are unqualified. But, the delivery cannot be all 6m long, so it is stipulated that positive deviations are allowed, but negative deviations are not allowed. (When the length of the fixed length is not more than 6m, the allowable deviation is expanded to +30mm; when the length of the fixed length is greater than 6m, the allowable deviation is expanded to +50mm)
3. Double ruler
The fixed size cut according to the order requirement is called a double ruler. When the delivery is made in multiple lengths, the length of the galvanized seamless pipe delivered must be an integer multiple of the length (called single length) in the order contract of the purchaser (plus the raw edge). For example, if the purchaser requires a single length of 2m in the order contract, then the length is 4m when cut into double length, and 6m when cut into triple length, and one or two saw cuts are added respectively. The amount of kerf is specified in the standard. When the scale is delivered, only positive deviations are allowed, and negative deviations are not allowed.
4. short ruler
The length is less than the lower limit of the length of the indeterminate length specified in the standard but not less than the shortest length allowed is called a short ruler. For example, it is stipulated in the standards for steel pipes for fluid transportation that 10% (calculated by number) of short steel pipes with a length of 2-4m are allowed in each batch. 4m is the lower limit of the indeterminate length, and the shortest length allowed is 2m.