CL251-1A 70×60mm Zinc Alloy 180° Heavy-Duty Adjustable Hinge with Matte Chrome Finish (Optional Positioning Function)

Full Technical Specifications

• Model Variants:
  • CL251-1A: Standard version (no positioning function, free rotation)
  • CL251-1AZ: Positioning version (holds at 60° and 120° open positions)
• Overall Dimensions: 70mm width × 60mm height × 10mm thickness
• Maximum Opening Angle: 180°
• Material: High-pressure die-cast zinc alloy hinge body + stainless steel pivot pin and decorative cover
• Surface Finish: Matte chrome (satin metallic finish, scratch-resistant, anti-corrosion, premium appearance)
• Mounting Holes: 4 pieces Φ5.4 through holes, center distances 40mm horizontal × 30mm vertical
• Positioning Angles (CL251-1AZ only): 60° and 120° detent positions
• Core Features: Heavy-duty load-bearing, adjustable installation, optional integrated positioning detents

Core Product Features & Advantages

1 High-Strength Die-Cast Zinc Alloy with Matte Chrome Finish

One-piece high-pressure zinc alloy die casting delivers excellent structural rigidity, impact resistance and reliable heavy load-bearing capacity. The refined matte chrome finish creates a uniform satin metallic surface that resists scratches, fingerprints and corrosion, presenting a premium professional appearance suitable for visible exterior mounting on high-end equipment enclosures.

2 Stainless Steel Pivot Pin and Decorative Cover

The stainless steel pivot pin provides superior wear resistance, corrosion protection and long-term rotational durability compared to standard steel pins. The matching stainless steel decorative cover conceals the pin assembly for a clean, finished appearance while adding an extra layer of protection against dust and moisture ingress.

3 Optional Integrated Positioning Function (CL251-1AZ)

The CL251-1AZ variant features an integrated positioning detent mechanism that securely holds the cabinet door at 60° and 120° open positions, enabling hands-free operation during maintenance, wiring and component access. This eliminates the need for separate door stays or prop rods, improving workplace safety and operational efficiency. The standard CL251-1A offers unrestricted free rotation for applications where positioning is not required.

4 180° Full Flat Opening Angle

The 180-degree maximum opening angle enables the cabinet door to lay completely flat against the cabinet side panel, eliminating operational blind zones and providing full unobstructed access for internal wiring, component replacement, equipment inspection and routine maintenance work.

5 Robust 70×60mm Plate with Four-Point Mounting

The oversized 70×60mm mounting plate provides a broad surface for excellent load distribution, while the 4×Φ5.4 mounting holes (40×30mm spacing) allow M5 screws to securely fasten the hinge to both cabinet frame and door. The four-point fixation pattern ensures robust and stable installation on heavy cabinet doors, resisting sagging and deformation under long-term frequent opening and closing.

6 Adjustable Installation for Precise Door Fit

The hinge design allows for minor positional adjustment during installation, enabling installers to achieve proper door alignment, consistent gap spacing and smooth operation. This adjustability compensates for minor sheet metal fabrication tolerances and ensures a professional fit on large or heavy cabinet assemblies.

Application Fields

1. Heavy electrical control cabinets, low-voltage distribution boxes, frequency converter enclosures and PLC equipment housings
2. CNC machine tool safety guards, automation equipment protective doors and industrial machinery access panels
3. Medical equipment housings, laboratory analytical instruments and environmental monitoring control boxes (positioning version recommended for hands-free maintenance)
4. Outdoor communication cabinets, energy storage battery boxes and waterproof monitoring equipment enclosures
5. Heavy-duty sheet metal tool cabinets, large instrument test equipment casings and industrial console doors
6. Food processing equipment, stainless steel sanitary cabinets and cleanroom facility enclosures
7. Test bench cabinets, industrial workstation enclosures and equipment requiring frequent door access
8. Applications where hands-free door positioning at fixed open angles improves operational efficiency and safety

Installation & Maintenance Guidelines

Step-by-Step Installation Procedures

1. Determine the installation positions on both the cabinet frame and door panel according to the dimension drawing
2. Mark and drill 4×Φ5.4 through holes at 40mm horizontal × 30mm vertical spacing on both the frame and door panel
3. Align the hinge halves against the mounting surfaces and fasten with M5 screws through all four holes on each half
4. For CL251-1AZ positioning version: verify that the door clicks securely into the 60° and 120° detent positions
5. Test the 180° opening movement for smooth rotation and verify hinge stability under door load
6. Adjust the hinge position slightly if needed to achieve proper door alignment and consistent gap spacing
7. Retighten all screws after final alignment to prevent loosening from vibration

Installation Quantity Recommendation

• Door height ≤700mm: Install 2 hinges symmetrically
• Door height 700mm to 1200mm or heavy steel door: Install 3 hinges for balanced load distribution and sag prevention

Maintenance Instructions

1. Suitable for both indoor and mildly corrosive outdoor environments; for extreme coastal salt spray or strong chemical environments, regular inspection is recommended
2. Wipe the matte chrome surface periodically with a soft dry cloth to remove dust, grease and moisture; avoid abrasive cleaners that may scratch the satin finish
3. Apply a small amount of dry lubricant to the stainless steel pivot pin every six months to maintain smooth and quiet rotation
4. For CL251-1AZ positioning version: test the 60° and 120° detent positions quarterly to ensure proper engagement; clean the detent mechanism if positioning becomes weak
5. Inspect mounting screw tightness quarterly, especially on equipment subject to continuous vibration
6. Inspect the matte chrome plating annually for chips or scratches; touch up with matching paint if necessary to maintain corrosion protection

Product Summary

CL251-1A is a premium 70×60mm heavy-duty adjustable hinge manufactured from die-cast zinc alloy with matte chrome finish, featuring a stainless steel pivot pin and decorative cover, four-point Φ5.4 mounting and 180° maximum opening. Available in standard free-rotation (CL251-1A) and 60°/120° positioning (CL251-1AZ) variants, it offers robust load-bearing capacity, corrosion resistance and optional hands-free door positioning, making it an ideal hardware solution for heavy electrical cabinets, CNC machinery, medical equipment, automation enclosures and various industrial applications requiring durable support and convenient operational features.

CL251-1A zinc alloy heavy duty adjustable hinge 180 degree matte chrome stainless steel pin cover 4-Φ5.4 mounting positioning function industrial cabinet equipment hinge