Prime-Line U 9970 Deadlock – Jimmy-Resistant Design Prohibits Forced Entry by Spreading of Door Frames – Single Cylinder Diecast Metal Lock With a Brass Finish and Angle Strike (Single Pack)

Works very well. It was also very easy to install

My old lock stopped working after 30 years. I did not feel like taking it apart to fix the inside lock. This was a perfect match and fit in the same space including the holes for the screws. The weight was slightly lighter than the original but just as sturdy. The keys turned easily on both sides with no pressure. Security reinstated...The local hardware stores were either sold out or double the price. This was worth the short wait.

This is a pretty good deadbolt, especially for the price. As I think has been mentioned, the hardware that comes with it is kind of sub-par. That said, I got extra long screws because my door frame didn't have a lot of solid wood right where the plate makes contact to the door frame, so really long screws were necessary to ensure that the plate will stay put even if an intruder gives the door a good kick. I did re-use the screws from my old deadbolt to attach the cast portion.Something that's a bit aggravating to me is that there's apparently no standardization regarding the actual dimensions or screw locations. This would have made replacing the old deadbolt with the new one a lot easier.One other plus is the keys are basically the same as the common Kwikset style, and the ones that come with the deadbolt are nice quality.Something to beware of is the bolts for the tumbler assembly itself may have to be shortened depending on the thickness of the door. They are designed to be able to snap off about 3/8" of the tips, but I had to use a combination of tools along with brute force to snap them off (it wasn't easy to do). I would have used the bolts from my old tumbler assembly, but the thread pitch was completely different (again, an issue of no standardization).

My Dad installed this lock at least 20 years ago. It finally quit working. The cylinder would turn but the locking mechanism would not engage. It was not available locally at the 3 places I checked so I went to Amazon to get it. It is just like the old one and fits exactly. This made it easy for me to install with no problems. The door is 70 years old. If this new lock quits working, I will probably have to replace the door instead of the lock. Glad I found it on Amazon, and really glad the style has not changed since my Dad bought the first one. Recommend it for durability and safety. If you are installing it on a door that has never had a lock like this, it will be more complicated. I am not that skilled. The instruction are very clear and explain how to do it, and templates are included.

Easy to install, sturdy, works perfect.

I recently needed, on a very short time fuse, to replace this kind of lock on an outside door to my house. The old lock must have been at least 40 years old. To my very pleasant surprise, exactly the same kind of lock was readily available on the Amazon website. Had exactly the same mechanism, dimensions (including mounting screw holes), and door frame pieces. I had to work to remove the mounting screws for the old lock, but installing the new lock was a very simple task after that -- no new drilling! Had to replace all of the old keys. But otherwise this was a WOW!

Cheap quality

I had a need to pass local home inspection and my 35+ year old double cylinder lock wouldn't pass. So, I bought this with the hope I could just replace the inside piece and leave the other older existing parts installed. Got the lock, unscrewed four screws that hold the lock in place and viola, it fit perfectly! Old key and strike mechanism were fine to work with the new inside lock that now has a code compliant knob to lock and unlock the door. Couldn't be happier!