Overview & Technology:
The SHOWA GIKEN NC Series and NCL Series Rotary Joints (Rotary Unions), engineered by SHOWA GIKEN INDUSTRIAL CO., LTD. (Japan), are high-performance fluid transfer units designed for high-speed spindles in CNC machine tools and industrial processing rolls. Utilizing proprietary mechanical seal technology constructed from advanced materials like Carbon, Ceramic, and Silicon Carbide, these joints guarantee zero leakage and consistent operational stability under high pressures.

Key Features & Highlights:
• Specialized Structural Classifications:
  - NC Series: Dual-passage (Duplex) structure featuring an integrated internal siphon pipe (e.g., outer casing 25A - internal pipe 10A, outer casing 40A - internal pipe 15A), enabling concurrent fluid supply and return circulation within a single compact envelope.
  - NCL Series: Compact single/dual passage configurations designed for smooth fluid conveyance, low resistance, and consistent pressure.
• Self-Tightening Thread Orientations:
  - Right-Hand Thread (RH): Self-tightens with clockwise shaft rotation.
  - Left-Hand Thread (LH): Self-tightens with counter-clockwise shaft rotation.
• Precision Dual Ball Bearings: Substantially lowers starting and running frictional torque, minimizes mechanical vibration, reduces noise levels, and saves motor energy consumption.

Durability & Heavy-Duty Construction:
The housing is precision-machined from pressure-resistant bronze alloys and JIS-compliant stainless steel. The units offer outstanding resistance to chemical corrosion, handle thermal fluctuations smoothly, and provide long-lasting service life under heavy operating conditions without demanding maintenance.

Practical Value for QA/QC:
Deploying SHOWA GIKEN NC / NCL Series rotary unions ensures uniform cooling and heating flow rates, prevents seal blowouts and unscheduled machine stops, extends CNC tool life, and maintains consistent machining surface precision.

• Manufacturer: SHOWA GIKEN INDUSTRIAL CO., LTD. (SGK)
• Product Category: Industrial Rotary Joint / Rotary Union
• Series: NC Series & NCL Series
• Country of Origin: Japan
• Applicable Media: Coolant / Water, Hydraulic / Lubricating Oil, Compressed Air, Saturated Steam
• Maximum Operating Temperature: Up to 100°C - 180°C (depending on media and seal configuration)
• Maximum Operating Pressure: Up to 1.0 - 1.5 MPa (~10 - 15 bar)
• Maximum Rotation Speed: 1000 - 3000 RPM (depending on nominal port size and spindle design)
• Connection Standards: JIS / RC Standard Thread (or optional NPT)

DETAILED MODEL DESIGNATIONS:
• NC 25A-10A LH: Duplex dual passage rotary joint, outer body 25A (1"), internal pipe 10A (3/8"), Left-Hand Thread (LH).
• NC 20A-8A RH: Duplex dual passage rotary joint, outer body 20A (3/4"), internal pipe 8A (1/4"), Right-Hand Thread (RH).
• NC 40A-15A RH: Duplex dual passage rotary joint, outer body 40A (1-1/2"), internal pipe 15A (1/2"), Right-Hand Thread (RH).
• NC 40A-15A LH: Duplex dual passage rotary joint, outer body 40A (1-1/2"), internal pipe 15A (1/2"), Left-Hand Thread (LH).
• NCL 25A RH: NCL series rotary joint, nominal port size 25A (1"), Right-Hand Thread (RH).
• NCL 40A LH: NCL series rotary joint, nominal port size 40A (1-1/2"), Left-Hand Thread (LH).

DESIGNATION SYSTEM NOTES:
• NC [Outer]-[Inner]: Duplex coaxial circulation rotary joint.
• NCL: Compact high-performance rotary joint series.
• RH (Right Hand): Clockwise tightening thread direction.
• LH (Left Hand): Counter-clockwise tightening thread direction.