In the process of purchasing seamless steel pipes, we often encounter several steel pipe length terms. If we cannot fully understand these terms, hidden dangers will often be buried in the signing of the contract, which will bring inconvenience or heavy losses to our later use. Therefore, we should fully understand these terms in the procurement process and confirm the reasonable length of seamless steel pipe we need:
Delivery length: The delivery length is also called the length required by the user or the length of the contract.
The standard has the following provisions on the delivery length:
①Normal length (also known as non-fixed length): Any length within the length range specified by the standard and no fixed length requirement is called ordinary length. For example, the structural pipe standard stipulates: hot-rolled (extrusion, expansion) steel pipe 3000mm ~ 12000mm; cold drawn (rolled) steel pipe 2000mm ~ 10500mm.
② Length of fixed length: The length of fixed length should be within the usual length range, a certain fixed length dimension required in the contract. However, it is impossible to cut out the absolute fixed length in actual operation, so the standard stipulates the allowable positive deviation value for the fixed length. Since the yield of seamless steel pipes with a ruler length has a greater decline than the usual length, it is reasonable for the manufacturer to ask for a price increase.
③Multiple ruler length: The multiple length should be within the normal length range, and the single ruler length and the multiple of the total length should be indicated in the contract (for example, 3000mmx3, that is, 3000mm).
3 multiples, the total length is 9000mm). In actual operation, the allowable positive deviation of 20mm should be added on the basis of the total length, and the incision allowance should be reserved for each single length of the ruler. Taking the structural pipe as an example, the notch allowance is specified: 5~10mm for outer diameter ≤ 159mm; 10-15mm for outer diameter > 159mm.
If there are no provisions for the length deviation and cutting allowance in the standard, it should be negotiated by both parties and indicated in the contract. The double-length length is the same as the fixed-length length, which will also bring about a substantial reduction in the finished product rate for the production enterprise, and the price increase is basically the same as the fixed-length length.
④ Range length: The range length is within the usual range. When the user requires a certain fixed range length, it should be indicated in the contract.
For example: the usual length is 3000~12000mm, and the range fixed length is 6000~8000mm or 8000-10000mm.
Although the range length is looser than the fixed-length and double-length length requirements, it is much stricter than the usual length, which will also bring about a reduction in the yield of seamless steel pipes for manufacturers.