I have a question concerning deadbolts. Care to enlighten?

[jeremy]

deadbolts cannot be returned by end pressure.

Correction:

Well-built deadbolts and deadlocking latches, when properly installed, can not be retracted by pressing on the end of the bolt or latch with anything but extreme force. Improper installation is common. Improper alignment often makes deadlocking latches into non-deadlocking latches. As for many deadbolts, an "end pressure" vulnerability becomes present when the bolt strike hole is not cut deep enough to allow full extension of the lock bolt. The shallowness of that hole is commonly overlooked when installing a modern deadbolt with 1" throw in place of a similar deadbolt that had only a 1/2" throw.

[vector40]

Are you saying that an installation that allows the deadlatch to be only partially depressed means you can push back the latch with heavy (but less than you'd need with a flawless installation) force? That doesn't make sense to me.

[Varjeal]

That is indeed true and is indeed the case. Unless the bolt is fully thrown, it is not in a deadlocked position.

Depending on the amount of gap between frame and door, it may be very easy to fashion a hook to apply pressure to the bolt and thus bypass it. Generally it is not worth attempting this, however, because one can't really tell if the bolt is fully engaged just by looking at it.

The easiest way to tell if this is occuring is to open the door, and fully engage the bolt with the T-turn. Next, retract the bolt fully, close the door (stand on the inside) and once again operate the T-turn. If it goes to the same position as with the door open, you are o.k. If not, then the hole is not deep enough to fully contain the bolt and must be modified to do so for a proper fit.

When doing this, also insure that the knob lock on the bottom is engaging IT'S latch properly as well. That is, with the door closed normally, the latch is within the strike plate and the deadlocking button depressed against the edge of the strike plate.

Btw Kasky: Opening locks that are not your own without express permission (ESPECIALLY in a school ) is illegal. DON"T do it. Also, talk like that puts a person on a fast-track to getting banned from this site. We do not tolerate illegal activity here. Only pick/manipulate locks that are your own and preferrably those that aren't being used to secure something.

[EGOOT247]

The origional question was answered thouroughly, but I'd like to add something...
We have a double-thing at my house: there is a deadbolt and a door-knob latch on the doors in my house. When the deadbolt is thrown, the door needs to be unlocked before opened, regardless of what side you are on, but when the door-knob lock is locked, I can still open the door from the inside without unlocking it.

Good night!

I can EDIT?!?! Since When?!?!?!
This is an edit. I've never edited, and thought I couldn't, but sure enough, there was the button. I had no need to edit this post, but the button was there, so I HAD to press it.

[vector40]

Oh, I'm sorry. I completely misread that post. Never mind me.