Downgraded or secondary quality HSS tubes are usually sold in bundle. They are downgraded due to some imperfection on a section of a tube or on parts of a lot. The most common defects are the following:
|Visible outer welding||Different lengths within a same lot|
|Weld Joint (buttweld)||Faulty welding (split)|
Other types of defects can also cause a downgrade. In general, lots that are sold contain a material loss of less than 10% of the total weight of a bundle. The purchase of secondary quality tubes is ideal for contract work that require cutting along the length.