National Hardware N178-822 V1308 Universal Knob Latch in Silver,1-1/2,1-3/4,3", Metal/Zinc

The first one I bought I could not get to lock at all so I returned it. When I received the replacement, I had the same problem with the new one so I knew I was doing something wrong -- it was my fault and I suspect the first one was not defective like I originally thought. So in case you buy one of these, I will give you a couple pointers that I figured out that were not in the instructions. The only instructions you get is what's written on the back of the cardboard package and it has several images telling you what each part is named but not how it is assembled.The external knob rotates regardless if it is in the locked or unlocked position. This seems awkward compared to a regular door knob. I'm used to trying to turn the knob and it will not rotate when it is locked and this is not how this one works. Of course when it is locked, you can turn the knob but still not open the door because it will not turn the handle on the inside of the door.First thing to note is that you cannot lock it with the key. On the inside door, there is a small latch that you slide up and down to lock and unlock the door. I even thought this part was defective but it wasn't. It seemed the latch would not move and was completely stuck. What was not said is that you must move the inside handle so it is completely in the middle (I call that the home position) and then the latch will move up and down. This is obvious once you assemble it because springs from the knob portion return it to that position by default but if you're playing with it before final assembly, it's not so obvious. So if your door is unlocked and closed and you wish to lock it. The only option is to open the door, slide the latch to the locked position and then close the door.To unlock, you insert the key and turn it 90 degrees and return to the home position and remove the key. This will cause the system to move the latch to the unlocked position. Now you can rotate the knob and it will connect with the inside handle and then you can open the door.You need three holes in your door. Two are used for screws that go all the way from the inside part to the outside part and the center hole that is used to connect the outside knob to the inside handle. The screw holes are made to be one of two specific distances apart. I'm not sure of the exact distance because I was replacing an older defective unit so the holes were already there. The screws go from the inside handle part to the outside knob so you will not see the screws or have access to them when the door is closed (from the outside anyway). However, the screws will not automatically thread into the knob hardware. This is supplied with some inserts that you have to put into pre-set holes that are at standard distances. There are four holes and you use two of those four holes depending on how far your screw holes are. Use pliers to screw in those inserts that match the distance of your holes. Select the proper locations to put those inserts into.The assembly was a bit confusing. There were two different shafts that slide into the knob but I didn't know, at first, how to use them. It seemed to work just fine with just one of those shafts -- the hollow one. The door handle turns and it will also turn the inside handle so it works with just the one. However, if you lock the door, you will not be able to unlock it with the key unless you also use the second shaft. It slips iside the hollow one and then both go through the center hole and into the round knob. The center shaft goes deeper into the knob than the outer one. The center shaft is the one that turns with the key and the outer shaft is the one that turns when you rotate the knob.The final problem that I encountered is that the thickness of the door is very important. Apparently mine is too thin so I couldn't tighten the screws all the way. If I do, there is too much pressure applied to the shafts that goes between the inside and outside parts and that makes the knob and latch difficult to rotate. Even if you were successful in applying enough pressure to turn them, the spring to make them return back to the home location is not strong enough. So I keep my screws loose and it works good enough for now. I plan to fix this problem by making a shim about 1/16" that will go between the handle and the door that will make it work like a thicker door.Giving this 4 stars instead of 5 for poor instructions and the inflexibility of using different thickness doors. Also, didn't like the non-standard locking mechanism where you cannot lock it with the key and the knob turns even when locked.

Installed easily—as long as you have the right tools, which are very few but necessary.

Great product. Compared to less expensive screen door knobs with key locks, this one works and works well.

For the money it got the job done. The lock switch was a bit stiff and small. I think in time it should wear and become easier. I installed for my mom to give her a sense of security but in reality how secure is a little screen door lock....it keeps honest people out. Overall for the money it gets the job done. I think if I had drilled the hole in the door out a bit larger the spring return of the handle wouldn't incur friction. As it is the spring can't over come the friction of the shaft thru the door and requires turning it back manually. This is No fault of the lock just an installer tip that you may need to drill the thru hole in the door in some cases to open the tolerance some. Also be aware the directions require you cut metal parts for thiner doors so you may need a cutting tool like a hack saw if your door width falls on the lower side of the advertised range.

The holes didn't line up.

A little cheap for a lock

works good wrong color but whatever

Looks like it will break before summer ends. Hits striker latch in the right place but the latch has too much spring compared to the handle shaft thickness. It’s already kinda wobbly

Works great, easy to install. Instructions weren’t the easiest to read but once I figured it out it was a breeze. Love that it has a lock.

Screen handle