Double hung window locks can be effective countermeasures against forced break-ins. They come in various colors such as black, white and aluminum, and are made of materials such as die-cast and hardened steel. Below are three types of double hung window locks.
The keyed double hang window lock is a security lock that can be enabled and disabled with a key. It's installed at the upper rail of the window sash. There are two main types of keyed lock. The bolt-action keyed lock and the fin-type keyed lock. Both types of keyed locks effectively prevents forced entry even if the glass window is broken. Keyed locks can be customized in various ways to meet your requirements.
Swivel Action Lock
Swivel action lock, also called keeper, provided medium security for your double hung windows. It is not a keyed lock, instead, a swivel action lock have a snib that is locking and can be swiveled from left to right to attached and detach the snib.
Lag screws can serve as a do-it-yourself security system for your double hung windows. All you need is a couple of lag screws drilled into the recessed washers of the sashes. With a special key, the lag screw can be tightened and loosened to lock and open the windows.