MIAO JIN 12 Pcs 12mm Brass Barrel Hinges Hidden Invisible Cabinet Furniture Hinges Concealed 180 Degree Opening Angle

These are 10mm or 0.394”. Use a 25/64” bit which is 0.390”. I ended up centering mine at 10/32” from the edge. 1/4” was too close and 3/8” too far. Make sure you have proper depth. And set them in flush. Once you tap them, they aren’t coming out - unless you “disassemble” then (i.e. destructive testing).

Overall these are really good but you do need to be very precise when you use them. I was making a flip top desk and I wanted hidden hinges for the top. I was glad that I had 12 of them because I used a few to prototype and that was a really good idea. You need to be precise in two things specifically: 1) you need to specifically use a 10mm drill bit...imperial bits won't cut it. 2) You need to be very precise in where you place the holes...there's not any way to make adjustments after the fact. I ended up making a jig that allowed me to match the holes on the two pieces precisely and it has worked great. The hinges seem strong....I've got 8 of them holding up a cherry desktop that has a computer monitor bolted to it and they're doing just fine.

Some are saying theae are fragile, and they might be a little, but I found them to be plenty sturdy if you handle them with care. I drilled a 25/64" hole for them, widened the top of the opening a little by angling the drill bit a little, then carefully tapped the hinge into the hole with the edge of a small L-bracket (unscrew the little set screws first). I the tightened the set screws until they started to creak. At first try, one set of holes wasn't positioned correctly, and I had to drill a second set of holes. I had thought I was going to have to destroy the hinge to get it out - that's what another reviewer had said - but I loosened the set screws, grabbed the hinge bars with pliers, gently wriggled the hinge out of the errant holes, and was able to reuse it. I used four hinges to make am hinged 3/4" table top that is about 4' x 25" and weighs 15-20 pounds, and they seem to be holding up well.

These were perfect for my husband who is making a custom chess board. They were exactly what we were looking for! Allowed the board to be flush, hardware was sturdy and of high quality

Several of the units fell apart while try to install. Not a quality product. Will not but again

No instructions were included with the hinges and the product description doesn’t have a link to any. Failed the first time installing as they weren’t close enough to the edge. Instructions would be helpful.

Good quality, nice quantity for the price

I use alot of these.heres the scoop.Dialing them in is crucial and can be menacing.Some are stiff and some are not.unscrew the hinge tension screw before installing.use a quality 25/64 brad point drill bit for the 10mm hinges and swab the hole with a q-tip loaded up with paste wax.helps to ease them in