Holes in the Plug

[Guitar_J]

I'm examining a Kwikset "security" Deadbolt, I took out the plug and noticed that there are holes to the right of the holes the pins are in, what are they called? and what are they for?

[zeke79]

Those holes are for construction keying. You should be able to do a search here to find out more information.

[HeadHunterCEO]

I also wonder about that

i assumed they had something to do with the fabrication of the plug

[Mad Mick]

As explained previously (by Marso if I'm correct) the extra holes are for receiving ball bearings used in construction keyed locks. The construction crew has a set of keys which is used to operate the lock normally, whilst they are working on the property. Once the property is handed over to the customer, the customer's key lifts the ball bearings above the shear line and the operation of turning the plug aligns the bearings with the extra holes in the plug. Once these bearings drop into the holes, the construction keys no longer work. The idea is that your typical construction crew may forget to hand in the keys for the property, or have duplicates made. Replacing the locks upon receiving the property, or the use of a construction keyed system guarantees against the other keys being used for unauthorised entry.

I think that the ball bearings are placed between the key/driver pins and never reach above the shear line when the construction key is used. The different bitting of the property owner's key is enough to raise the ball bearings above the shear line during the first use, and upon rotating the plug, they drop into the extra holes, never to be used again.

Result - the property owner's key works as a normally keyed lock would and the construction key is no longer valid.

I could be wrong on some points, but that's the general gist of it.

[HeadHunterCEO]

i have heard of these locks before

now it makes sense

thanks

[zeke79]

As explained previously (by Marso if I'm correct) the extra holes are for receiving ball bearings used in construction keyed locks. The construction crew has a set of keys which is used to operate the lock normally, whilst they are working on the property. Once the property is handed over to the customer, the customer's key lifts the ball bearings above the shear line and the operation of turning the plug aligns the bearings with the extra holes in the plug. Once these bearings drop into the holes, the construction keys no longer work. The idea is that your typical construction crew may forget to hand in the keys for the property, or have duplicates made. Replacing the locks upon receiving the property, or the use of a construction keyed system guarantees against the other keys being used for unauthorised entry.

I think that the ball bearings are placed between the key/driver pins and never reach above the shear line when the construction key is used. The different bitting of the property owner's key is enough to raise the ball bearings above the shear line during the first use, and upon rotating the plug, they drop into the extra holes, never to be used again.

Result - the property owner's key works as a normally keyed lock would and the construction key is no longer valid.

I could be wrong on some points, but that's the general gist of it.

Good explanation Mad Mick. That covered everything that I did not have time to type out yesterday.