There are approximately 45 types of hot rolled (hot extruded) stainless steel pipes with diameters ranging from 54 to 480mm, and about 36 types with wall thicknesses from 4.5 to 45mm. There are a total of 65 types of cold drawn (rolled) stainless steel pipes with diameters from 6 to 200mm, and 39 types with wall thicknesses from 0.5 to 21mm.
Outer and inner surfaces of precision stainless steel thick-walled tubes must not have cracks, folds, crazes, fissures, rolled folds, delamination, and scabs, etc. Such defects must be completely removed (unless specifically for machining purposes), and the wall thickness and outer diameter must not exceed the negative deviation after the removal. Minor surface defects that do not exceed the allowable negative deviation can be left as is without removal.
Stainless steel straight bars require a specific depth, as well. Hot-rolled, hot-extruded steel pipes, stainless steel pipes with a diameter of 140mm or less, and wall thickness not exceeding 5% of the nominal thickness, should have a depth of 0.5mm or less. Cold drawn (rolled) stainless steel pipes should not exceed 4% of the nominal wall thickness and have a depth of 0.3mm or less.































