1. Could you simply define what a lock threshold is ?
Explanation in my apt search I want to make sure that the locks operate properly without loose or missing thresholds. Could you tell me what to look for (simply)!
2. what is a double cylinder lock?
3. what is a deadbolt lock with a saw resistant boult projection or rim mounted deadbolt?
4.what are window sashes?
5 .what are window chains?
6. could you send an attachment examples shown in pictures?

1.'ll guess. We know what a door threshold is, so a lock threshold has to be that piece of metal that is the stationary part of the lock. I suppose a deadbolt would go into a lock threshold in a door frame.

For the part that is in the door jamb of a door knob lock system. That's the door strike. It allows you to close the door without turning the door knob.

2. A key is required on both sides of the door. Usually in conjunction with key operated deadbolts.

3. A deadbolt is a essentially a long bar. The internals can have something hard that spins, thus resisting a saw. A rim mounted deadbolt is just that, usually surface mounted on the inside of the protected area.

3. The part of a window that moves.

4. I'll guess. Very similar to door chains. They allow the window to open partway for ventilation. In the case of a door chain. It allows one to open the door about 6"