NHN A-8KH / AFD-8KH Center Hang Type Auto Hinge

NHN Auto Hinge™ Center Hang – A-8KH / AFD-8KH

The NHN Auto Hinge™ Center Hang series includes both the A series and AFD-M series configurations for concealed self-closing swing doors. The two versions share the same basic door-size and weight rating for this model, but their top-pivot systems differ. The A series uses a screw-type top pivot, while the AFD-M series uses a double-shaft top pivot and silicone buffering oil.

Technical Specifications

A and AFD versions are listed for this model and must be specified separately.

• Model: A-8KH
• Series: A series
• Maximum door width: 800 mm
• Maximum door height: 2000 mm
• Minimum door thickness: 36 mm
• Maximum door weight: 50 kg
• Maximum opening angle: 180° right- or left-hand one-side opening
• Standard closing force: 6.9 N·m
• Applicable door weight: up to 31 kg/m²
• Applicable door type: Steel door (wicket door only)
• Top pivot: Screw-type top pivot (N-21B)
• Spring set system: Roll-in system
• Closing force adjustment: adjustable by winding the spring
• Closing speed adjustment: adjustable through the speed-control gear
• Door opening direction: right or left, one-side opening
• Model-specific difference: screw-type top pivot; no silicone-buffering-oil specification is given for the A series.

AFD-M series — AFD-8KH

• Model: AFD-8KH
• Series: AFD-M series
• Maximum door width: 800 mm
• Maximum door height: 2000 mm
• Minimum door thickness: 36 mm
• Maximum door weight: 50 kg
• Maximum opening angle: 180° right- or left-hand one-side opening
• Standard closing force: 6.9 N·m
• Applicable door weight: up to 31 kg/m²
• Applicable door type: Steel door (wicket door only)
• Top pivot: Double-shaft top pivot (NKOS-M18)
• Spring set system: Roll-in system
• Closing force adjustment: adjustable by winding the spring
• Closing speed adjustment: adjustable through the speed-control gear
• Door opening direction: right or left, one-side opening
• Model-specific difference: double-shaft top pivot and silicone buffering oil.

Model Comparison

Construction and operation

The center-hang design is built into the door construction, keeping the automatic closing mechanism concealed and maintaining a clean door appearance. The hydraulic control mechanism works with the spring mechanism to provide controlled closing. The closing force can be adjusted by winding the spring, while the closing speed can be adjusted through the speed-control gear.

One complete set consists of the main hinge, receptive base, top pivot and decorative rubber plates. The standard installation uses the roll-in spring set system. A fixed-type floor receptive base is available as an option where the sliding receptive base is not suitable.

SEO article

NHN A-8KH and AFD-8KH are concealed center-hang automatic hinges for heavy swing doors. Both configurations provide 180° one-side opening and are designed around the same model-specific door dimensions and weight rating. The main distinction is the top-pivot construction: the A series uses a screw-type pivot, while the AFD-M series uses a double-shaft pivot and silicone buffering oil.