Polar Tangro 6 Inch Invisible Door Hinges (2 Pack), 3D Adjustable Hidden Door Hinges for Doors, 180 Degree Swing Heavy-Duty Zinc Alloy Concealed Hinge, 88 lbs Load-Bearing, Brushed Silver Finish

If you're looking for an application with hidden hinges, these work well and look great. Besides being completely invisible when installed, they look good when exposed with the door open and come with covers to hide the screws. They can handle fairly heavy doors (see specifications). As with lots of high-end hardware, the dimensions are metric. The hinge is 25mm wide, just short of an inch. Installation isn't easy, but it's what is expected from this type of hardware. There are good instructions in the box. Cutting/routing the holes to recess the hinges can be a challenge, as each hole has 2 different depths and curved ends. I would definitely make a template if installing several of these. I did a practice installation on some scrap and would recommend doing one before cutting into an expensive door and frame. If your door jamb is standard 1"x X wood, there may not be much wood left to screw the hinge in, as the recesses are quite deep. The inner recess will go all the way through the jamb. On the jamb side I'd consider replacing the provided screws with longer screws that extend into the framing. The hinges are highly adjustable to change the gap and horizontal and vertical alignment. It may take a bit of practice to get them right, but they give you the hex wrenches in the kit to make the adjustments. If you're want a really tight fit, remember that wood will expand and contract with moisture and temperature, so make appropriate allowances in the fit. Also be aware that due to the width of the hinges, they'll need to be installed indoors 1-3/8" thick or greater.

These are just as good as the options that are 3x the money. They are extremely heavy duty and smooth. I'm using them on a hidden bookshelf door that might have a couple hundred pounds on them at any given point. My one knock is on installation. I wasn't expecting it to come with an installation jig or anything. And I know the measurements are in the product listing pictures ....but at a printable template or guidance on a template would be great. As these type of recessed hinges are notoriously difficult to get perfect. Luckily I was able to pull it off without wasting any material.

Hard to install if you have not clue what to do but I built a frame as a hideaway door and it wasn't under the best circumstances. But the door I built weights 70-80 lbs and it's holding.

This pair of hinges are call invisible because when the door is closed you can't see them at all. They have to be mortised in to install and that take precision measurements and marking skills as well as specific tools. They are very strong and good looking.

These puppies are heavy! Very well built. The instructions have only metric dimensions which may or may not be a problem to some. The action is smooth and works well.

I’ve almost been dreading the installation of these hinges, but it’s done and the result is excellent. These hinges accomplish their purposes very well- hidden, strong, and smooth operation. Installation takes longer: I used a 1” hole saw for cutting the rounded ends, an oscillating saw to cut the rabbet sides, wood chisels to remove wood, and a rotary file to clean up and make necessary adjustments. I found the installation instructions to be cryptic (only metric drawings) and no help at all for the adjustment process.

I'll be putting these in a door soon, but in comparison to more expensive makes of this type of hinge, it appears well made. The only thing I don't like on these cheaper hinges is the cheap plastic cover - I'd rather have exposed crews and just paint them with flat or matte black. I try to show in the video what to expect more realistically.

I ordered and sent to a friend. They arrived quickly and are just as described.