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Knowledge of spiral steel pipe identification
Feb 16, 2019

When buying the spiral steel pipe, the first from the appearance size, use cursor card whether simple measuring tool measuring the actual size than indicated size (both on general spiral steel pipe rolling specification) about a specification or more (such as Ø 219 spiral steel tube standard inner diameter is 2188 mm + / - 0.4 mm, but most and inferior spiral steel pipe inner diameter is about 218 mm).Spiral steel tube knowledge, at the same time some fake spiral steel tube through the way to deceive people's vision, so from the steel tube surface end surface observation for flat oval, and the normal material end surface should be basically round;Secondly, from the surface quality, shoddy spiral steel pipe due to the use of unqualified raw materials rolling, its surface quality is poor, often with scars and other defects, the overall rough feeling.At the same time, some small steel mills due to heating temperature, rolling speed is not enough, the surface color slants red;Third, most of the normal spiral steel pipe factory in large bundles of packaging, bundles of steel are hanging with the metal signage corresponding to the real, indicating the manufacturers, steel brand, batch number, specifications and inspection code.However, due to the poor production conditions and the absence of large hoisting equipment, most of the fake steel bars are packed in small bundles (about 10 pieces are bound) or bulk.


No metal label, no quality guarantee.


  1. The actual size is about one specification smaller than the nominal size. Dealers can make huge profits by purchasing goods with actual weight and delivering goods with theoretical weight.

2. Low intensity.