In modern interior design, minimalism and clean lines have become the new aesthetic standard. People are moving away from bulky, visible hardware and instead choosing elegant, streamlined solutions. One of the key elements driving this trend is the concealed hinge, also known as a hidden hinge or invisible hinge.
Unlike traditional hinges that remain visible when the door is closed, concealed hinges are completely hidden inside the door and frame. This design not only enhances visual harmony but also provides durability, smooth operation, and safety. Moreover, 3D adjustable concealed hinges allow for fine-tuning in three directions—height, depth, and width—making installation and later adjustment much easier.
In this article, we’ll guide you step by step on how to install concealed hinges on folding doors, a type of modern door often used in apartments, offices, and villas. Whether you’re a homeowner, installer, or door hardware distributor, this guide will help you understand the essential process, tools, and considerations for achieving a professional installation result.
How to Install a 3D Adjustable Concealed Hinge
Step 1: Choosing the Right Concealed Hinge
Before starting installation, selecting the correct concealed hinge for your folding door is crucial. The hinge type must match your door’s thickness, height, and weight.
When buying your hardware, remember:
- Measure your door dimensions. For example, most interior doors are around 2100mm in height. In general, two concealed hinges are sufficient for a standard-sized door.
- Check the door thickness. This determines the hinge model you can use. For folding doors, which are often thinner than solid wood doors, ensure the hinge’s depth fits within the door material.
- Confirm the door weight. The hinge load capacity should be equal to or greater than the door’s total weight. We SDH provide concealed hinges with the load capacity from 15 kg to 300 kg.
- Ask your supplier about the hinge compatibility, especially for rebated or flush-type folding doors.
At SDH Hardware, our 3D adjustable concealed hinges are available in various sizes and materials (zinc alloy or stainless steel). Each model complies with EN1935 standards and has undergone over 200,000 cycle tests, ensuring long-lasting performance and stability.
Step 2: Preparing for Installation
If you’re installing concealed hinges for your own folding door, you have two options:
- Ask your door manufacturer to pre-cut the hinge slots before delivery. This ensures perfect alignment and avoids mistakes during manual installation.
- Hire a professional installer or carpenter who is familiar with concealed hinges. This saves time and prevents damage to the door edges during slot cutting.
Having the correct tools is also essential. You’ll need:
- A drill or hole cutter (to create the hinge pockets)
- A chisel or router for fine adjustments
- A pencil and ruler to mark hinge positions
- Screws, covers, and an Allen key (these are usually provided in the SDH hinge package)
Step 3: Marking and Cutting the Hinge Slots
Now the installation process begins.
- Mark the hinge positions on both the door frame and the door leaf.
- The hinge should be placed no more than 5mm from the door edge.
- If the gap is larger, the door might jam or scrape when opened.
- Use the supplied installation template or make a simple drilling jig from scrap wood to keep your drill steady. This prevents deviation and ensures the holes are precisely aligned.
- Cut or drill the hinge pockets carefully using your hole cutter.
- Clean out wood chips and dust, ensuring the hinge cavities are smooth and flat.
📽️ For a clearer understanding, you can watch our full concealed hinge installation video on SDH Hardware’s. The video demonstrates the entire process on a real folding door setup.
Step 4: Installing the Concealed Hinges
After cutting the hinge slots, you can now proceed with installation.
By the way, for standard flush doors, follow these steps:
Attach the hinge to the door leaf first. On the back of each hinge, you’ll find a marking labeled “DOOR” — this side should be mounted on the door leaf.
Secure the hinge with the provided screws.
Once both hinges are attached to the door, lift the door carefully and position it so the hinges fit perfectly into the slots on the door frame.
Fix the frame-side screws to hold the hinge in place.
Make sure the door opens and closes freely before tightening all screws fully.
Step 5: Adjusting the Door – 3D Adjustment
The main advantage of using 3D adjustable concealed hinges lies in their flexibility. After the door is installed, you can fine-tune the alignment in three directions:
- Vertical adjustment
- Horizontal adjustment
- Compression adjustment
Use the Allen key provided in your SDH hinge accessory pack to turn the adjustment screws gently. With just a few turns, your folding door will fit perfectly and move smoothly.
Step 6: Finishing Touches
After completing the adjustment, cover the screw heads with the provided decorative covers to give a neat, high-end appearance.
Finally, open and close the folding door several times to ensure silent, smooth operation. If the door rubs slightly, recheck the 3D adjustment points and fine-tune them again.
Congratulations — your concealed hinge installation is complete!
Installation Display
Why Choose SDH 3D Adjustable Concealed Hinges
Our concealed hinges are trusted by door manufacturers, builders, and hardware distributors worldwide for their premium quality and stable performance. Here’s why SDH stands out:
1. Complete Accessories & Easy Installation
Each hinge set comes with a manual, screws, covers, and Allen keys. Clear instructions and optional video tutorials ensure that even first-time users can achieve professional results.
2. Durability and Testing
Every SDH hinge passes 200,000 opening and closing cycles under load testing conditions, ensuring long-term durability and reliable performance even in high-frequency environments like hotels, offices, or villas.
3. Surface Finishes
We offer multiple finishes to match modern interior styles:
- Matt black finish – passes 240-hour neutral salt spray test
- Satin nickel, PVD gold, and other finishes – pass 96-hour salt spray tests
These finishes not only enhance corrosion resistance but also complement different door materials such as wood, aluminum, or composite panels.
4. Customization
SDH supports custom hinge sizes, colors, and branding for distributors and OEM clients. Whether you’re supplying residential or commercial projects, our concealed hinges can be tailored to meet your specific design and load-bearing requirements.
Final Thoughts
Installing 3D adjustable concealed hinges on folding doors is a smart way to achieve a modern, minimalist look without sacrificing durability or functionality. By following the steps above—selecting the right hinge, marking accurately, drilling carefully, and adjusting precisely—you can create a flawless door system that’s both aesthetic and long-lasting.
As more people embrace hidden hardware and frameless door concepts, concealed hinges are quickly becoming the new standard in door design. Whether you’re renovating your home or managing a building project, SDH’s concealed hinge solutions offer professional quality, versatility, and peace of mind.
