Small Diameter Steel Pipe Outer Circle 10mm 5mm Inner Diameter Wall Thickness 2.5mm Hollow Iron Pipe Carbon Steel Round

(1) Specification: the specification requirements of spiral steel pipe should be listed in the import and export trade contract. Generally, it should include the standard brand number (type code), the nominal diameter of the steel bar, the nominal weight (mass), the specified length and the allowable value of the above indicators. Our country standard recommends spiral steel pipe series with nominal diameters of 8, 10, 12, 16, 20, 40mm. Supply length is divided into fixed length and double length. China's export rebar length selection range is 6 ~ 12m, Japanese rebar length selection range is 3.5 ~ 10m.
(2) Appearance quality: ① Surface quality. The surface quality of rebar is stipulated in the relevant standards, requiring that the end should be cut flat and straight, the surface shall not have cracks, scarring and folding, and there shall be no harmful defects in use; (2) Allowable value of dimension deviation. The bending degree of rebar and the requirements of steel bar geometry are specified in the relevant standards. As stipulated in Chinese standards, the bending degree of straight bar is not greater than 6mm/m, and the total bending degree is not greater than 0.6% of the total length of bar.

Delivery length is also called customer required length or contract length. The standard has the following provisions on delivery length:
A, ordinary length (also known as irregular length) : where the length is within the standard length range and there is no fixed length requirements, are called ordinary length. For example, structural pipe standards: hot rolled (extruded, expanded) steel pipe 3000mm ~ 12000mm; Cold-drawn (rolled) steel pipe 2000mm ~ 10500mm.
B. Fixed length: the fixed length shall be within the normal length range and is a fixed length specified in the contract. But in practice, it is impossible to cut absolute length, so the standard stipulates the allowable positive deviation value for the length of definite length.
The structural pipe standard is:
The yield of fixed length pipe decreases more than that of normal length pipe, so it is reasonable for the manufacturer to raise the price. Add price range each enterprise is not consistent, add price 10% or so on base price foundation commonly.
C. Length of multiples: the length of multiples shall be within the normal length range, and the single length and the multiple of the total length shall be indicated in the contract (e.g. 3000mm×3, i.e. 3000mm 3x, with a total length of 9000mm). In practice, the allowable positive deviation of 20mm should be added to the total length, plus the incision allowance should be left for each single ruler length. Take the structural pipe as an example, the specified incision allowance: outer diameter ≤159mm is 5 ~ 10mm; Outer diameter >159mm is 10 ~ 15mm.
If there is no length deviation and cutting allowance in the standard, it shall be indicated in the contract through negotiation between the supply and demand parties. Double ruler length is the same as fixed ruler length, which will greatly reduce the yield of production enterprises. Therefore, it is reasonable for the production enterprises to raise the price, which is basically the same as the fixed ruler length.