Cylinder Head CLASSIC NBU

AirsoftParts CLASSIC NBU Cylinder Head for Bore Up Air Seal Systems
The NBU version is dimensioned for Bore Up systems and must be combined with an NBU cylinder and NBU nozzle. Two O-rings of different diameters seal the space between the head and cylinder. The first is slightly smaller for easier insertion of the head into the cylinder, while the second has a larger diameter and provides the main seal. The shaped and stepped impact ring with a hardness of 70 ShA helps cushion and distribute the impact of the piston head. The internal transition is rounded for smoother flow of compressed air towards the nozzle. The duralumin body features an electroless nickel-plated finish that creates a uniform, smooth surface with high wear and corrosion resistance. According to the manufacturer, the surface hardness after plating reaches 660–850 HV (58–63 HRC), while the low-friction surface promotes smooth NBU nozzle movement. The head weighs 11.5 g, is designed for V2 and V3 gearboxes with the corresponding NBU air seal system, and the manufacturer specifies a maximum recommended spring of M150. Made in the Czech Republic.
Key Features

NBU Design for Bore Up Air Seal Systems
The enlarged design corresponds to an NBU / Bore Up air seal system. For proper operation, the cylinder head must be combined with the corresponding NBU cylinder and NBU nozzle.

Double Seal With O-Rings
The two O-rings have different functions: the smaller one makes inserting the head into the NBU cylinder easier, while the larger one provides the main seal between the cylinder head and cylinder.

Shaped 70 ShA Impact Pad
The stepped impact ring with a hardness of 70 ShA helps cushion and distribute mechanical shock when the piston head impacts and reduces unwanted local..