Custom Sheet Metal Enclosures for Indoor & Outdoor Waterproof Dustproof Electrical Junction Boxes
Custom Sheet Metal Enclosures for Indoor & Outdoor Waterproof Dustproof Electrical Junction Boxes
Project Background
As industrial electrical systems and outdoor infrastructure expand rapidly, a leading electrical equipment provider launched a 2026 large‑scale customization project for waterproof and dustproof electrical junction box enclosures. These enclosures protect wiring terminals, control modules, and circuit components in harsh and stable environments alike.
Key requirements included:
IP65 waterproof and dustproof protection
Dimensional tolerance ≤±0.03mm
High structural rigidity and deformation resistance
Corrosion resistance for long‑term use
Compatibility with standard electrical interfaces
Stable mass production quality
Distinct surface finishes for indoor and outdoor environments
Sanjun Hardware was selected for its precision sheet metal capabilities, professional sealing structure design, and mature dual‑environment surface treatment technology.
Manufacturing Process of Core Components
The electrical junction box consists of the main enclosure, sealed door panel, cable entry ports, and mounting base. All production follows ISO 9001 quality standards and industrial electrical enclosure specifications.
1. Material Selection & Pre‑treatment
Main enclosure and door panel: 1.2mm galvanized steel sheet for high structural strength and corrosion resistance.
Pre‑treatment: Fully automated ultrasonic degreasing, derusting, and phosphating to create a clean, high‑adhesion surface base ideal for powder coating.
2. Core Manufacturing Craftsmanship
Precision Laser Cutting: 8000W fiber laser cutter with ±0.02mm tolerance, using nitrogen assist gas to minimize heat distortion and maintain material integrity.
CNC Bending & Forming: 9‑axis CNC bending machine with custom jigs, ensuring springback ≤0.02mm and consistent sealing‑groove dimensions.
Sealing Structure: Precision‑milled sealing grooves for waterproof gaskets, standardized cable entry holes, and mounting positions.
Indoor & Outdoor Electrostatic Powder Coating
Indoor version: Indoor‑grade electrostatic powder coating, providing smooth finish, good adhesion, anti‑rust performance, and aesthetic consistency for indoor environments.
Outdoor version: Outdoor‑grade electrostatic powder coating with anti‑UV, anti‑rain, anti‑corrosion, and weather‑resistant properties, ensuring stable performance under long‑term outdoor exposure.
Coating thickness is strictly controlled at 60–120μm for uniform coverage and durable protection.
Both achieve strong adhesion, corrosion resistance, and long service life.
3. Challenge: Structural Strength vs. Lightweight Design
The enclosure must be lightweight for installation yet rigid enough against impact.
Solution: FEA‑optimized internal reinforcing ribs improve structural strength by 25% without extra weight.
4. Challenge: High Batch Consistency
Customer required uniform appearance, size, and performance across 6,000 units.
Solution: Automated production lines + SPC real‑time monitoring + sampling inspection per 100 units.
Project Outcomes
Delivery: 6,000 units completed and delivered 5 days ahead of the 45‑day schedule, with 100% pass rate in all tests.
Performance: Enclosures operate stably in both indoor distribution systems and outdoor engineering sites with no water ingress, dust buildup, or coating failure.
Partnership: The client signed a 3‑year strategic cooperation agreement, appointing Sanjun Hardware as the exclusive sheet metal supplier for its full series of electrical junction boxes.
