Material Composition: They are produced from alloy steel with high wear resistance or heat-treated steel (hardened to higher HRC values). Stainless steel may be preferred for some parts against corrosion. Precision Machining: The surfaces of the parts are machined with micron-level precision on CNC machines and have undergone grinding/polishing processes to minimize friction. Sealing and Lubrication Grooves: Circular grooves (groove slots) seen on cylindrical bodies are for the placement of sealing elements (O-ring, seal) or for the homogeneous distribution of hydraulic oil. Drain and Connection Holes: The side holes, more prominent in the second image, are designed for the discharge of pressurized fluid or for fixing the part to a mechanism with a pin.