The term stainless steel is applied to a range of iron based alloys which rely on their chromium content for resistance to corrosion. The chrome thats containd in the alloying oxidized and generates a hard invisible surface protection layer that prevents further corrosion - until the surface gets damaged and the process repeated itself.
The steels used by Flexseal have 17%-18% Chromium content and 8% -11% Nickel content and are in full compliance with the manufacturing standards and has a life span up to 100 years.
In poorly drained gravel ground and the existence of industry and coal mining and in cases where the grounds and the ground water with a chloride concentration more than 1000 ppm the quality tend to pittng corrosion.
Because of this Flexseal offers two different steel grades. By standard all used steel pieces are out of autentic stainless steel according to DIN 1.4301 (V2A).
For the contaminated grounds mentioned above and also for special sealings we can equip our bushes with a steel quality according to DIN 1.4401 (V4A) if it is desired. An increased molybdenum addition in the alloying improves the corrosion-resistance of the steel by a multible.
authentic, stainless steel - DIN 1.4301 - AISI 304 - V2A
authentic, stainless steel - DIN 1.4401 - AISI 316 - V4A