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AirsoftParts Cylinder Head CLASSIC NBU
AirsoftParts CLASSIC NBU cylinder head is a CNC-machined head made from EN AW 6012 T6 duralumin for Bore Up air seal systems in V2 and V3 gearboxes. Two O-rings provide sealing in the NBU cylinder, the shaped 70 ShA impact pad cushions piston impacts, and the electroless nickel-plated finish provides high durability and low friction for smooth NBU nozzle movement.
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AirsoftParts replacement seals for the CLASSIC NBU cylinder head (2 pcs) are a service set of O-rings designed to restore proper sealing of the Bore Up air seal system. Regular replacement of worn seals helps reduce unwanted air leakage. The manufacturer recommends replacement approximately every 10,000 BBs fired or once a year.
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AirsoftParts NBU full cylinder is a polished stainless steel upgrade part for NBU / Bore Up air seal systems in AEGs with long inner barrels from 400 mm. The enlarged 24.7 mm inner diameter provides a higher air volume than a standard cylinder and requires an NBU piston head and NBU cylinder head. The smooth polished surface helps reduce seal friction.
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AirsoftParts NBU duralumin nozzle is a precision CNC-machined nozzle for NBU / Bore Up air seal systems, made from EN AW 6012 T6 duralumin. An internal O-ring helps seal the connection with the cylinder head and reduce air leakage. The nozzle is designed exclusively for use with an NBU cylinder head and weighs only 0.8–1.3 g depending on the length variant.
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4UANTUM SEAL Silicone Grease for Sealing by 4UAD in a transparent finish. High-viscosity sealing grease. Ideal for sealing repairs and preventing leaks from damaged O-rings. Suitable for electric AEGs, manual, GBB, CO2, and HPA gas guns. Content: 15 ml. Easy application with a pen applicator.
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Specna Arms silicone grease in a practical 50g package is an essential service lubricant for airsoft gun maintenance. It is particularly suitable for O-rings, seals, AEG pneumatic systems, GBB valves and HPA systems. It helps reduce friction, protects sealing components from drying out and extends their service life.
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AirsoftParts CLASSIC NBU Cylinder Head for Bore Up Air Seal Systems
AirsoftParts CLASSIC NBU cylinder head is a CNC-machined component for AEG air seal systems made from EN AW 6012 T6 duralumin. 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 localized stress.
Rounded Transition for Airflow
The internal section of the head uses a rounded transition towards the outlet, promoting smooth flow of compressed air from the NBU cylinder into the nozzle.
Electroless Nickel-Plated Finish
Electroless nickel plating creates a uniform, hard and smooth surface layer with high wear and corrosion resistance. The low-friction surface is also beneficial for smooth NBU nozzle movement.
Technical Specifications
- Designation: HV-CLASS-NBU
- Type: cylinder head for AEG
- Size: NBU / Bore Up
- Material: EN AW 6012 T6
- Manufacturing: CNC machining
- Maximum recommended spring: M150
- Sealing: 2× sealing O-ring
- Surface finish: electroless nickel plating
- Surface hardness after plating: 660–850 HV (58–63 HRC)
- Impact pad: shaped stepped ring
- Impact pad hardness: 70 ShA
- Weight: 11.5 g
- Compatibility: V2 and V3 gearboxes with the corresponding NBU air seal system
- Required cylinder: NBU / Bore Up
- Required nozzle: NBU
- Country of manufacture: Czech Republic
Frequently Asked Questions (FAQ)
Can the CLASSIC NBU Cylinder Head Be Used With a Standard Cylinder and Nozzle?
No. The CLASSIC NBU version is designed for Bore Up air seal systems and must be combined with an NBU cylinder and NBU nozzle. It is not intended for use with a standard cylinder and standard nozzle.
What Is the Difference Between the CLASSIC and CLASSIC NBU Cylinder Heads?
The CLASSIC NBU is dimensioned for Bore Up air seal systems and requires the corresponding NBU cylinder and NBU nozzle. The standard CLASSIC, on the other hand, is designed for standard-size air seal systems.
Why Does the Cylinder Head Have Two Sealing O-Rings?
The first O-ring has a slightly smaller diameter and makes inserting the head into the cylinder easier. The second is larger and provides the main seal between the cylinder head and NBU cylinder.
What Are the Benefits of Electroless Nickel Plating?
The electroless nickel-plated layer creates a hard, uniform and smooth surface with high resistance to wear and corrosion. The smooth surface also reduces friction as the NBU nozzle moves over the cylinder head.
| Variants | NBU |
| Color | Silver |
| Body/receiver material | Metal |