Acoustical Steel Doors Systems Hardware Infomation

Proper selection of hardware for use on acoustic door assemblies is very important. The following are suggestions to assist the hardware specifier in this task:


The weight of an acoustic door demands a comparable hinge. On the higher rated STC assemblies (STC46 and above), Security Metal Products provides their own Gravity Glide cam-lift type hinge.  Hinges supplied by others should be the ball bearing extra heavy weight type.


Most of the popular cylindrical locks are furnished with a large rose trim which, when used with a 2-3/4” backset lock, will interfere with the jamb mounted perimeter seal assembly. As a result, cylindrical locks with levers or knobs should always be specified with 3-3/4” backset.  Mortise lock backsets are unalterable but since they are furnished with a much smaller trim or escutcheon plate there is no interference when furnished with levers. Unit type locks should never be specified in view of the requirement to remove a large portion of the door edge for installation.


Mortise, Rim and Surface Vertical Rod exit devices are fully compatible. Concealed Vertical Rod exit devices cannot be used due to the large portion of door core required to be removed full height of the door for installation of the rod assemblies.


The use of push and pull plates without benefit of a latching device is not recommended since there is nothing to keep the door in contact with the perimeter seal at the lock edge of the door.


Special consideration must be used when specifying closers for doors hung on cam-lift hinges. This type of hinge causes the door to rise as it opens and puts undo stress on closers that are not equipped with a pivoting arm. Concealed closers and floor closers cannot be used. Overhead holders typically have rigid arms and cannot be used with cam-lift hinges.


Mortised bottom flush bolts interfere with any type of mortised door bottom seal. Manual type top bolts are not a problem. We recommend surface bolts for the bottom or, in the case of fire doors, the type of flush bolt assemblies furnished with fire bolts. Automatic flush bolts should be avoided unless required by local codes.


Thresholds are typically provided by Security Metal Products. These have a flat and smooth top surface compatible for use with mortised door bottoms. Fluted or abrasive thresholds should never be used as they tend to destroy the bottom seal.


The Adams Rite UltraLine 7440 Electric Strike is the only one that is compatible with Security Metal Products higher rated STC assemblies (above STC46). In order to maintain a quiet environment, it’s necessary for the acoustic door to be tight to the perimeter seal. This typically forces the latch bolt of the lock or exit device against the strike gate causing pressure to the jaws of the electric strike. This strike is designed to open electrically under 35lbs of preload.


Electrified locks with manual latch retraction are compatible, but any lock with electric latch retraction will have a problem similar to the electric strike.

It should be noted that Security Metal Products provides hardware standoff brackets for most hardware normally designed and intended for stop mounting. Hardware should never be mounted directly to the sound seal assembly. Please refer to Security Metal Products Installation Instructions for details and more information.