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We are installing a panic door and can't figure out and/or find on internet what is this hook-like thing on a striker/panic bar:

enter image description here

It does not respond to pressing on the bar and appears to be just getting in the way, making it impossible to open the door by pressing on the bar, defeating the whole purpose of this device.

Does anybody know what is it?

We are considering just sawing it off.

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  • 31
    As a general rule, just removing things you don't understand is a bad idea.
    – Reid
    Oct 14 at 16:03
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    No worries. No anti-shims were harmed.
    – wha7ever
    Oct 14 at 17:20
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    On sawing off things you don’t understand: fs.blog/2020/03/chestertons-fence
    – Philip
    Oct 16 at 1:46
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    I don't understand your comments :-)
    – Florian F
    Oct 16 at 15:38
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That looks like an anti-shim feature, similar to this pin next to the bolt of a simple handle:

anti-shim pin

When the anti-shim component is depressed, it prevents the latch from being pressed by a screwdriver or other tool that is slid between the door and the frame.

If I'm correct, that component is supposed to slide against the door frame but not get caught in the recess for the latch.

If you provide the model number of your hardware, it should be easy to confirm if this is correct.

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  • I think you're thinking along the right lines, although a deadlatch needs to be depressed to allow the main latch to work, not the other way around as you wrote it Oct 13 at 23:41
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    @ThreePhaseEel The way you said it sounds backwards to me. When the deadlatch is depressed, that locks the main latch from being pressed externally. When the deadlatch is extended, that is what allows the main latch to be depressed by the strike plate as the door swings closed. If the main latch is locked in place when the deadlatch is extended, the door would not be able to latch when it closed.
    – Moshe Katz
    Oct 13 at 23:52
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    I may be the confused one here :) Oct 13 at 23:54
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    When the door is open both latch and deadlatch are extended. In that case the latch and deadlatch can be pushed in. The door can close. When the door is closed only the latch is extended. Then the latch cannot be pushed in. You need to push the handle to open the door.
    – Florian F
    Oct 16 at 15:47
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That is quality, pricey Class I or Class II door hardware. It would be a crying shame to take a hacksaw to it. You didn't buy that from AliExpress... you probably got that from a competent vendor who gives support. Use the support!

You aligned your strike incorrectly

The strike, or strike plate, is the rectangular hole in the door jamb that the latch goes into.

You are supposed to align your strike plate so that thing won't fall into the hole.

As Moshe Katz deduced, it is exactly a dead-latch or anti-shim feature. When you close the door, this pice does not fall into the hole and is pushed inward.

When pushed inward, it locks the latch so it can't be pushed inward freely, e.g. by a credit card or screwdriver attack.

But try it. Jab on the latch and see how it retracts freely. Then hold down the dead latch and jab again. Doesn't retract freely anymore!

However, when the dead latch is pushed inward, the latch will still operate if actuated by the knob, lever or push bar.

Now, on the simpler dead latches like in Moshe Katz's photo, it has a reasonable failure mode if the latch is misaligned: the dead latch pin will retract with the latch. This one may not be like that.

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    Didn't this latch come with a strike plate? A correct strike plate would force the latch to behave as described in this answer and prevent the behavior you are experiencing. You may need to align things better on the door, but a suitable strike plate for this device ought to make that obvious. It OUGHT to make it so if the latch works at all, it works correctly. Can you add a photo to your question of the strike plate, alone, and if possible one of it mated to the latch?
    – jay613
    Oct 14 at 13:43
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    "As Moshe Katz deducted" It would actually be the word deduced. I made an account on this site just because that bothered me haha.
    – Hacker
    Oct 16 at 15:26
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    @Hacker Welcome to the site! Unfortunately I recently switched platforms and this one's autocorrect and I don't always see eye to eye. Oct 16 at 17:35
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    There's a great talk by Deviant Ollam on door security, which covers the need for Dead Latches like this: youtu.be/4YYvBLAF4T8, starting at around 8:45, 9:00ish. Also covers the failure mode mentioned @10:30, where the door can be over-closed and the dead latch falls into the strike plate, disabling the protection. Oct 17 at 1:09

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