PRODUCTION | Piston – Liner – Ring

Optima has an exceptionally long tradition in manufacturing large-bore pistons for 4-stroke large-bore engines (piston diameter from 130 to 250 mm) for vessels and power plants. We are able to produce more than 100 different pistons for various engine types and brands. Our aim, grow the piston production over 300 mm. 

Varieties of Pistons are:

Aluminum Pistons

Aluminum pistons are light and have ideal thermal conductivity properties. They feature integral reinforcement parts, such as cast iron ring carriers, steel parts for defined thermal expansion, or ceramic fiber reinforcements of aluminum oxide, depending on the intended application.

Articulated Pistons (2 parts)

Articulated pistons are used in the construction of utility vehicle diesel engines when conditions are too harsh for aluminum pistons. They consist of a steel upper section and an aluminum piston skirt. Both these parts are connected with friction-locking by the piston pin. Compared with aluminum pistons, articulated pistons boast higher strength in the steel upper section. This makes them more resistant to high pressures and temperatures.

Steel Pistons (Monobloc)

Steel pistons are forged from highly heat-resistant steel with high-stress endurance. They withstand high ignition pressures, even at maximum temperatures. They are therefore used in heavy-duty diesel engines in utility vehicles and passenger cars, where they ensure maximum service life and superior reliability. Working in cooperation with various American and European engine manufacturers, Kolbenschmidt has successfully developed steel pistons for utility vehicles and passenger cars in recent years.


  • Aluminum Pistons: Aluminum pistons nowadays are typically designed for diameters up to 260 mm. The low weight of the piston and the high variety of bowl geometries are just two big advantages of the design. Ring carriers for reducing the wear of the first ring groove as well as a salt core cooling gallery for better cooling of the ring land and the bowl rim can easily be implemented. Electron beam-welded aluminum pistons can be used for higher peak cylinder pressures. This piston design combines the advantages of a forged piston skirt with the benefits of cast ring bands.
  • Forged Steel
  • Nodular cast iron



Our liners are produced in a centrifugal casting process with bore diameters of up to 320 mm. Optima boasts an extensive product range with over 200 cylinder liners. We produce using many kinds of coating and hardening methods. Like Gas Nitriding for heat treatment, TUFFTRIDE AB1 (hardness HRB 400~500), and many other production technologies. 


Our piston rings are suited for all types of combustion engines with cylinder diameters of up to 320 mm. OPTIMA piston rings are manufactured from cast iron and steel using the latest technologies, and their performance is optimized through high-quality coating processes. we offer cast iron models with chrome-ceramic coatings and steel rings with PVD coatings made of chromium nitride. PVD-treated rings exhibit extremely low wear and lubricating oil consumption—at the same time, the ring running profile is better maintained.