Screw is not the same screw! This phrase is especially true for Stainless Steel Pipe Fittings, which depend on the highest security and with little downtime.
The heart of a cutting ring fitting according to EN ISO 8434-1 (DIN 2353) is the cutting ring. In most cases, the specially designed and tested by Germanischer Lloyd Two edge cutting rings are used, which have shown themselves to be very precise and highly reliable a million times. The cutting ring seals the fully assembled screw in three prominent places.
The major advantages are:
Extremely good cut in
High tightness, no rust on the surface
No "set" of the cutting ring
Through the use of surface-coated coupling nuts, the tightening torque reduces up to 35%. Furthermore, a cold welding of stainless steel material is prevented in the thread.