The usual delivery length of square and rectangular tubes is 4000mm-12000mm, mostly 6000mm and 12000mm. The square rectangular tube is allowed to deliver short-length and non-fixed-length products not less than 2000mm, and it can also be delivered in the form of an interface tube, but the buyer should cut off the interface tube when using it. The weight of short-length and non-fixed-length products shall not exceed 5% of the total delivery quantity, and for square and rectangular pipes with a theoretical weight greater than 20kg/m, shall not exceed 10% of the total delivery quantity