CL255 Zinc Alloy Black Powder Coated 180° Concealed Pivot Hinge (CL255-1 / CL255-3)

Full Technical Specifications

Model Variants:
- CL255-1: A=5.1mm, Ts=2.0mm (for 2.0mm door panel thickness)
- CL255-3: A=4.6mm, Ts=1.5mm (for 1.5mm door panel thickness)
Hinge Body Material: High-pressure die-cast zinc alloy
Pivot Pin Material: Solid steel
Surface Finish: Black powder coating (wear-resistant, corrosion-resistant, matte black industrial appearance)
Maximum Opening Angle: 180°
Base Plate Dimensions: 42mm width × 20mm height
Mounting Holes: 2 pieces Φ8.1 through holes, 20mm center spacing
Pivot Pin Diameter: Φ6mm
Top Plate Width: 38mm (24.8mm between mounting points)
Side Profile: 22mm width × 8.5mm depth × 20-22mm height
Door Cutout Size: 14mm width × 29mm height (for hinge recess)
Installation Type: Concealed pivot — base plate mounts to cabinet frame, steel pin inserts into pre-drilled hole in door panel
Core Features: Fully concealed hidden design, zinc alloy durability, black powder coat corrosion resistance, steel pivot pin, two door thickness variants, 180° full opening

Core Product Features & Advantages

1 Fully Concealed Hidden Design for Clean Exterior Appearance

The innovative concealed pivot design ensures that no hinge hardware is visible on the exterior of the cabinet door when closed, creating a seamless, clean and professional appearance. This hidden mounting solution is ideal for applications where aesthetic appearance is important, such as high-end equipment enclosures, server racks, control panels and visible exterior cabinetry.

2 High-Pressure Die-Cast Zinc Alloy Construction

The hinge body is manufactured from high-pressure die-cast zinc alloy, providing excellent structural rigidity, impact resistance and dimensional stability. The zinc alloy construction offers a good balance of strength and weight, ensuring reliable performance under repeated opening and closing cycles while maintaining precise dimensional tolerances.

3 Durable Black Powder Coat Finish

The black powder coating provides a uniform matte black surface that is highly resistant to scratches, abrasion, corrosion and UV fading. The powder coat finish creates a professional industrial appearance that matches standard black cabinet hardware, while providing long-lasting protection against environmental factors in both indoor and outdoor applications.

4 Robust Steel Pivot Pin for Smooth Durable Rotation

The solid steel pivot pin provides exceptional load-bearing strength and rotational durability, reliably supporting the cabinet door weight without bending or wearing over time. The precision-machined pin ensures tight clearance, low-friction rotation and smooth, consistent 180° opening and closing operation over tens of thousands of cycles.

5 Two Variants for Different Door Thicknesses

The hinge is available in two carefully calibrated variants to accommodate different sheet metal door thicknesses: CL255-1 (A=5.1, Ts=2.0) designed for 2.0mm thick door panels, and CL255-3 (A=4.6, Ts=1.5) designed for 1.5mm thick door panels. This ensures proper fit, optimal pivot alignment and smooth operation regardless of the cabinet construction standard.

6 180° Full Opening with Pivot Mechanism

The 180-degree maximum opening angle provides full unobstructed access to the cabinet interior, while the pivot mechanism enables the door to rotate smoothly around the steel pin axis. The pivot design eliminates the need for traditional barrel hinges on the cabinet exterior, providing a clean appearance while maintaining full functional access.

Application Fields

Electrical control cabinets, low-voltage distribution boxes, frequency converter enclosures and PLC equipment housings requiring hidden hinge solutions
CNC machine tool guards, automation equipment protective doors and industrial machinery access panels
Server racks, data center enclosures, communication equipment cabinets and IT infrastructure housings
Outdoor communication cabinets, energy storage battery boxes and waterproof monitoring equipment enclosures
Sheet metal tool cabinets, industrial console doors, workbench cabinets and premium storage enclosures
Test bench cabinets, laboratory equipment enclosures and environmental monitoring control boxes
High-end equipment enclosures, kiosks, point-of-sale systems and display cases where clean exterior appearance is critical
Aluminum profile industrial frames, mechanical equipment maintenance hatches and large test fixtures
Applications where traditional exposed hinges are aesthetically undesirable or physically obstructive

Installation & Maintenance Guidelines

Step-by-Step Installation Procedures

Select the appropriate variant based on door panel thickness: CL255-1 for 2.0mm doors, CL255-3 for 1.5mm doors
On the cabinet frame: mark and drill 2×Φ8.1 through holes at 20mm center spacing for the base plate mounting
On the door panel: cut a 14mm × 29mm recess opening at the corresponding position for the hinge body to pass through
Drill a Φ6 hole in the door panel at the pivot pin location to accommodate the steel pivot pin
Mount the hinge base plate to the cabinet frame using M8 screws through the 2×Φ8.1 holes
Align the door panel so that the steel pivot pin inserts into the pre-drilled Φ6 hole in the door
Verify that the hinge body properly passes through the 14×29mm cutout in the door panel
Test the 180° opening movement for smooth rotation and verify hinge stability
Adjust the mounting position slightly if needed to achieve proper door alignment and consistent gap spacing

Installation Quantity Recommendation

Door height ≤600mm: Install 2 concealed pivot hinges symmetrically (top and bottom)
Door height 600mm to 1200mm or medium-weight steel door: Install 3 hinges (top, middle, bottom) for balanced load distribution

Maintenance Instructions

Suitable for both indoor and outdoor environments; the black powder coat provides good corrosion resistance for most industrial conditions
Wipe the black powder coated surface periodically with a soft dry cloth to remove dust and grease; avoid abrasive cleaners that may scratch the powder coat finish
Apply a small amount of dry lubricant to the steel pivot pin every six months to maintain smooth and quiet rotation
Check the 2 base plate mounting screw tightness quarterly to prevent loosening from vibration
Inspect the black powder coating annually for chips or scratches; touch up with matching black paint if necessary to maintain corrosion protection
Inspect the steel pivot pin annually for any signs of wear, bending or excessive play
Verify that the door cutout and pivot pin hole remain properly aligned; re-adjust if door alignment shifts over time

Product Summary

CL255 is a concealed pivot hinge manufactured from high-pressure die-cast zinc alloy with a durable black powder coat finish and a robust steel pivot pin. Its fully concealed hidden design provides a clean seamless exterior appearance, while the zinc alloy construction and powder coat finish deliver excellent structural rigidity and corrosion resistance. Available in CL255-1 (for 2.0mm doors) and CL255-3 (for 1.5mm doors) variants, with 2×Φ8.1 base plate mounting, Φ6 steel pivot pin and 180° full opening, it is an ideal hidden hinge solution for electrical cabinets, machinery enclosures, server racks, communication equipment and various industrial applications requiring aesthetically clean, durable and reliable concealed door hardware.

CL255 zinc alloy black powder coated concealed pivot hinge 180 degree steel pin 2-Φ8.1 mounting holes hidden industrial cabinet equipment door hinge CL255-1 CL255-3