If there’s one upgrade I recommend to almost every homeowner who asks me how to harden a front door without replacing the whole lockset, it’s a door reinforcement lock like this one. The Prime-Line U 10827 Door Reinforcement Lock isn’t flashy, and it won’t show up in a smart-home app — but it does one job extremely well: it stops a door from being kicked or shouldered open, even after the primary lock has failed.
Here’s how it works. The Prime-Line Door Reinforcement Lock mounts on the door frame above (or below) your existing deadbolt and swings a hardened metal arm across the door edge when you’re home. Because that arm isn’t tied into the strike plate or the door jamb the way a standard deadbolt is, a battering-ram kick that would normally blow through a cheap strike plate has nothing to grab onto. Prime-Line rates it to withstand 800 lbs of force, and in my experience with similar reinforcement locks, that number holds up — this is genuinely one of the better “second line of defense” products I’ve installed for clients.
Installation is simple: four screws, a screwdriver, and about ten minutes. If you don’t get 3″ screws with the lock, swap the included hardware for the 3 – Inch Reinforced Door Screw Kit, screws that bite into the framing rather than just the door casing — longer ones meaningfully increase pull-out resistance.
One limitation worth being upfront about: this only works when someone is home to engage it before bed. It’s a supplemental night-lock, not a standalone security solution, and it doesn’t replace a quality deadbolt.
Bottom line: A cheap, fast, genuinely effective way to add forced-entry resistance to any inward-swinging door. Recommended as a nightly-use companion to your primary deadbolt, not a replacement for one.