CL253-9 30×40mm SUS304 Stainless Steel 180° Mirror Polished Ultra-Mini Countersunk Butt Hinge

Full Technical Specifications

Model Number: CL253-9
Overall Dimensions: 30mm total width × 40mm height × 1.5mm leaf thickness
Maximum Opening Angle: 180°
Material: SUS304 stainless steel
Surface Finish: Mirror polishing (highly reflective polished finish, corrosion-resistant, premium appearance)
Pivot Pin Diameter: Φ3.5mm
Mounting Holes: 4 pieces Φ3.5 through holes with Φ6.1×90° countersunk counterbores (2 per leaf), 20mm vertical spacing, 16mm horizontal spacing
Side Profile: 1.5mm leaf thickness
Design Feature: Rounded corners for safe, snag-free installation
Core Features: Ultra-compact micro size, full SUS304 corrosion resistance, mirror polished aesthetic, countersunk flush mounting, M3 flat head screw compatible, 180° full opening

Core Product Features & Advantages

1 Premium SUS304 Stainless Steel Construction

The entire hinge is fabricated from SUS304 stainless steel, providing excellent corrosion resistance, oxidation resistance and structural durability even in this ultra-miniature size. Suitable for both indoor and outdoor environments, including damp, coastal and mildly corrosive conditions, it maintains reliable performance over years of service without rusting or degrading.

2 Mirror Polished Finish for High-End Aesthetic Appearance

The precision mirror polishing creates a highly reflective, sleek metallic surface that elevates the visual quality of even the smallest equipment enclosures. In addition to its premium appearance, the polished surface resists fingerprints, is easy to clean and provides an extra layer of corrosion protection, making it ideal for medical, jewelry, luxury and consumer-facing applications where appearance is critical.

3 Countersunk Flush Mounting for Clean Snag-Free Exterior

The 4×Φ3.5 mounting holes are machined with Φ6.1×90° countersunk counterbores, allowing M3 flat head screws to sink completely flush with the hinge 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 visible exterior applications on small devices where every detail of appearance matters.

4 Ultra-Compact Micro Footprint for Space-Critical Applications

With an ultra-compact 30×40mm overall size and slim 1.5mm leaf thickness, this hinge is specifically designed for miniature and space-critical applications where standard-sized hinges simply cannot fit. The micro footprint with rounded corners allows it to be installed on tiny instrument panels, small control boxes, compact device housings and delicate enclosures without occupying valuable internal or external space.

5 180° Full Flat Opening Angle

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

6 Four-Point Countersunk Mounting with Φ3.5 Pivot Pin

The 4×Φ3.5 countersunk holes (2 per leaf) with 20mm vertical and 16mm horizontal spacing ensure secure and stable installation with M3 flat head screws. The Φ3.5 precision-machined pivot pin provides tight clearance, low-friction rotation and minimal wobble, delivering smooth and quiet operation over tens of thousands of open-close cycles.

Application Fields

Tiny electrical control boxes, compact junction boxes, miniature PLC enclosures and small distribution cabinets
Medical devices, portable diagnostic instruments, laboratory micro-equipment and environmental monitoring sensors
Miniature communication equipment, small server modules, compact signal transfer enclosures and IoT device housings
Jewelry boxes, luxury packaging, watch cases, premium gift boxes and decorative enclosures
Precision instrument panels, electronic test equipment casings, measurement devices and sensor housings
Small outdoor monitoring equipment, weather-resistant micro-instrument panels and compact coastal sensor enclosures
Premium compact furniture, small electronic casings, handheld devices and decorative enclosures where polished flush appearance is preferred
Marine micro-equipment, RV accessories, boat fixtures and outdoor miniature devices requiring corrosion-resistant stainless steel hardware
Model making, DIY projects, custom enclosures and precision engineering applications requiring micro-size flush-mount hinges
Food processing micro-equipment, small stainless steel sanitary boxes and cleanroom mini-enclosures

Installation & Maintenance Guidelines

Step-by-Step Installation Procedures

Determine the installation positions on both the cabinet frame and door panel according to the dimension drawing
Mark and drill 4×Φ3.5 through holes at 20mm vertical × 16mm horizontal spacing on both the frame and door panel
Machine 90° countersunk counterbores to Φ6.1 diameter on the mounting surface side to accommodate M3 flat head screws
Align the hinge halves against the mounting surfaces and fasten with M3 flat head screws through all four countersunk holes
Confirm that all screw heads are completely flush with the hinge surface and do not protrude
Test the 180° opening movement for smooth rotation and verify hinge stability
Adjust the hinge position slightly if needed to achieve proper door alignment and consistent gap spacing

Installation Quantity Recommendation

Door height ≤250mm: Install 2 hinges symmetrically
Door height 250mm to 450mm or medium-weight small door: Install 3 hinges for balanced load distribution

Maintenance Instructions

Suitable for both indoor and outdoor environments, including damp, coastal and mildly corrosive conditions; for extreme salt spray or strong chemical environments, regular rinsing with fresh water is recommended
Wipe the mirror polished surface periodically with a soft dry or slightly damp microfiber cloth to remove dust, fingerprints and grease; avoid abrasive cleaners or scouring pads that may scratch the mirror finish
Apply a small amount of dry lubricant to the Φ3.5 pivot pin every six months to maintain smooth and quiet rotation
Check M3 countersunk mounting screw tightness quarterly to prevent loosening from vibration
Inspect the polished surface annually for scratches or corrosion; for coastal applications, rinse with fresh water periodically to remove salt deposits
Due to the miniature size and 1.5mm thickness, avoid over-tightening screws which may cause deformation of the thin hinge plate
Inspect the countersunk holes periodically to ensure screw heads remain flush and have not backed out

Product Summary

CL253-9 is an ultra-compact 30×40mm mini butt hinge with rounded corners and countersunk flush mounting, manufactured from premium SUS304 stainless steel with precision mirror polishing. Its full stainless steel corrosion resistance, highly reflective polished finish, snag-free countersunk M3 flush mounting, micro-size space-saving design, Φ3.5 precision pivot pin and 180° full opening angle make it an ideal hardware solution for tiny electrical cabinets, medical devices, jewelry boxes, laboratory instruments, IoT sensors, outdoor micro-equipment and various precision applications requiring durable micro-size performance, a premium polished appearance and a clean flush exterior.

CL253-9 SUS304 stainless steel mirror polished ultra mini countersunk butt hinge 180 degree 4-Φ3.5 Φ6.1×90 countersunk holes 30x40mm Φ3.5 pin small industrial cabinet equipment hinge