CL257-2 Steel White Zinc Plated 105° Concealed Hinge — Left Hand (CL257-2-Z) / Right Hand (CL257-2-Y)

Full Technical Specifications

• Model Variants:
  • CL257-2-Z: Left-hand hinge (for left-side door swing)
  • CL257-2-Y: Right-hand hinge (for right-side door swing)
• Hinge Body and Pin Material: Solid steel
• Surface Finish: White zinc plating (rust-proof, wear-resistant, clean industrial appearance)
• Maximum Opening Angle: 105°
• Overall Dimensions: 47mm total length × 15.5mm width × 18.5mm height
• Body Length: 32mm (main body section), 25mm mounting section, 6mm end section
• Pivot Pin Diameter: Φ4mm
• Mounting Holes: 2 pieces Φ5.2 through holes with Φ9×90° countersunk counterbores, 20mm center spacing
• Side Profile: 15.5mm width × 18.5mm height, 2mm leaf thickness, 12mm height, 6.5mm internal depth
• Top Dimension: 11.4mm width, 8mm pin section
• Core Features: Left/right hand variants, steel construction, white zinc corrosion resistance, countersunk flush mounting, compact concealed design, 105° opening, Φ4 pivot pin

Core Product Features & Advantages

1 Left and Right Hand Variants for Flexible Door Configuration

The hinge is available in both left-hand (CL257-2-Z) and right-hand (CL257-2-Y) configurations, allowing designers and installers to select the appropriate hand based on the door swing direction. This ensures proper hinge orientation, optimal load distribution and smooth operation regardless of whether the door opens to the left or right, providing flexibility for various cabinet layout designs.

2 Solid Steel Construction with White Zinc Plating

The entire hinge, including both the body and pivot pin, is fabricated from robust solid steel for excellent structural rigidity and load-bearing capacity. The uniform white zinc plating forms a protective layer that effectively resists oxidation, rust and surface abrasion, providing reliable performance in standard indoor industrial environments while maintaining a clean and professional appearance.

3 Countersunk Flush Mounting for Clean Snag-Free Exterior

The 2×Φ5.2 mounting holes are machined with Φ9×90° countersunk counterbores, allowing M5 flat head screws to sink completely flush with the mounting surface. This creates a smooth, snag-free exterior that eliminates protruding screw heads, improving safety, aesthetics and ease of cleaning. The flush mounting is particularly suitable for concealed applications where a clean appearance is desired.

4 Compact Concealed Design for Space-Saving Installation

With a compact 47mm overall length and concealed mounting configuration, this hinge is designed for applications where space is limited and a clean exterior appearance is desired. The compact footprint allows it to fit neatly on cabinet frames and door panels without occupying excessive space, while the concealed design minimizes visible hardware on the cabinet exterior.

5 105° Maximum Opening Angle

The 105-degree maximum opening angle provides adequate access for internal wiring, component replacement, equipment inspection and routine maintenance work on most standard cabinet configurations. The angle is calibrated to prevent the door from striking adjacent equipment or walls while still providing sufficient operational access.

6 Φ4 Precision Pivot Pin for Smooth Rotation

The Φ4 precision-machined steel pivot pin ensures tight clearance, low-friction rotation and minimal wobble, delivering smooth and quiet operation over tens of thousands of open-close cycles. The solid steel pin provides reliable load-bearing capacity for medium-weight cabinet doors.

Application Fields

1. Electrical control cabinets, low-voltage distribution boxes, frequency converter enclosures and PLC equipment housings
2. CNC machine tool guards, automation equipment protective doors and industrial machinery access panels
3. Communication equipment cabinets, server boxes and signal transfer enclosures
4. Sheet metal tool cabinets, industrial console doors, workbench cabinets and storage enclosures
5. Test bench cabinets, laboratory equipment enclosures and environmental monitoring control boxes
6. Aluminum profile industrial frames, mechanical equipment maintenance hatches and test fixtures
7. High-volume electrical cabinet manufacturing and OEM equipment production requiring cost-effective reliable hinges
8. Indoor industrial applications where concealed flush-mounted hardware and left/right configuration are required
9. Applications where compact concealed hinge design with minimal visible hardware is preferred

Installation & Maintenance Guidelines

Step-by-Step Installation Procedures

1. Select the appropriate hand variant: CL257-2-Z for left-hand door swing, CL257-2-Y for right-hand door swing
2. Determine the installation positions on both the cabinet frame and door panel according to the dimension drawing
3. Mark and drill 2×Φ5.2 through holes at 20mm center spacing on the cabinet frame
4. Machine 90° countersunk counterbores to Φ9 diameter on the mounting surface side to accommodate M5 flat head screws
5. Align the hinge body against the cabinet frame and fasten with M5 flat head screws through the 2 countersunk holes
6. Confirm that all screw heads are completely flush with the mounting surface and do not protrude
7. Align the door panel with the hinge pivot pin and ensure proper engagement
8. Test the 105° opening movement for smooth rotation and verify hinge stability
9. Adjust the mounting position slightly if needed to achieve proper door alignment and consistent gap spacing

Installation Quantity Recommendation

• Door height ≤500mm: Install 2 hinges symmetrically (top and bottom), ensuring both are the same hand variant
• Door height 500mm to 900mm or medium-weight steel door: Install 3 hinges (top, middle, bottom) for balanced load distribution

Maintenance Instructions

1. Suitable for indoor dry environments; not recommended for long-term outdoor exposure, high-humidity areas, coastal salt spray or severe chemical vapor conditions
2. Wipe the white zinc plated surface periodically with a soft dry cloth to remove dust, grease and moisture
3. Apply a small amount of dry lubricant to the Φ4 pivot pin every six months to maintain smooth and quiet rotation
4. Check the 2 countersunk M5 mounting screw tightness quarterly to prevent loosening from vibration
5. Inspect the white zinc plating annually for chips or scratches; touch up with zinc-rich paint if necessary to maintain rust protection
6. Inspect the pivot pin and barrel assembly annually for any signs of wear, binding or excessive play
7. Verify that the left/right hand orientation remains correct and that the door opens and closes smoothly without binding

Product Summary

CL257-2 is a compact concealed hinge manufactured from solid steel with white zinc plating, available in both left-hand (CL257-2-Z) and right-hand (CL257-2-Y) variants. Its steel construction provides reliable structural rigidity, the white zinc plating offers corrosion protection for standard indoor environments, the countersunk Φ9×90° flush mounting with M5 flat head screws creates a clean snag-free exterior, and the Φ4 precision pivot pin ensures smooth 105° opening operation. With a compact 47mm concealed design and flexible left/right configuration, it is a cost-effective and reliable hardware solution for electrical cabinets, machinery enclosures, communication equipment, industrial consoles and various high-volume OEM applications requiring concealed flush-mounted hardware with proper hand orientation.