Important technical terms

Ferrite
Crystal type of iron (magnetic), which is characterized by a cubic body centered lattice structure.

Final cleaning
The final cleaning of seamless stainless steel tubes comprises of the following steps: pickling, rinsing with water as well as drying.

Finish
The finish of a seamless stainless steel tube gives details about its production (cold manufactured/hot manufactured) and surface condition (ground/polished/de-scaled/not de-scaled/etc.). The various types of finish are stated in DIN [German Industrial Standard] 17456 and DIN 17458.

Fitting
This generic term is used for conduit elements, which are utilized for branching, change of direction or cross section or also for closing a line. Fittings are standard elements, which are generally manufactured from the respective tubes by deforming or welding or in other cases are welded together from plate segments.

Fixed length
A determined tube length for seamless stainless steel tubes, which may be delivered with an admissible deviation of up to +/- 500 mm.

Flaring test
The flaring test serves the verification of the formability of tubes by expanding on a mandrel up to a determined amount without formation of incipient cracks.

Flattening test on tubes
The flattening test on tubes is mainly utilized for the verification of macroscopic external and internal defects as well as the assessment of deformability. During flattening of the tubes cross section up to a certain limit value, no incipient cracks may occur and no internal and external defects may become visible.