COATING

PHOSPHATING ( P ) : PHOSPHATE COATING ON ALL SURFACES

With phosphating, crystalline phosphates are deposited on all surfaces of the piston rings except chrome – plated areas.

The phosphate layer has a thickness of 0.002 – 0.005 mm. and improves the running in behaviour of the piston ring by increasing the adhesion of the oil.
Furthermore, the phosphate layer has a certain anti-corrosive effect during long storage periods even under damp conditions.

CHROME PLATING ( CR ) : RUNNING SURFACE CHROME-PLATED AND LAPPED

The electroplated chromium layer reduces wear on both the piston ring itself and on its friction partner, the running surface of the cylinder or liner. It thus helps to ensure that the total life of both the piston ring set and the engine is similar.
Both compression and oil control rings can be chrome plated.

NITRIDING ( NIT ) :

In this process, nitrogen atoms penetrate and diffuse into the base metal, significantly increasing the surface hardness. This coating is mostly used for steel top and oil rings. While it offers very good wear resistance, its scuff resistance is similar to chrome coating.