Surface-Mounted Electric Strike Solutions

July 2, 2019
Today, options are available that work with pullman latches and a rotating starwheel

My usage of electric strikes goes back to a time when companies offered only three or four different electric strike models. Locksmiths had to find creative ways to use them according to installation requirements. As electronic access control appeared customers began asking for electrified exit devices.

While more companies today offer internal kits for electrifying exit devices, this was not always the case. I remember making home made boxes to house available electric strikes of that era. A majority of exit devices use a pivoting pullman latch similar in action to a butt hinge. As the door is closed, the pullman latch folds into the exit device case and then expands into the strike plate when the door is fully closed. While pullman latches are strong and secure, tongues on existing electric strikes of the time did not always freely interact with pullman latches.

An additional problem with matching electric strikes of that era with exit devices was that the electric strike would have to be mortised into the door jamb. Since most exit devices are installed on fire exits, any changes to the door jamb affected the fire rating of the opening. This was all solved with the development of “no-cut” surface mounted electric strikes for use with exit devices.

Clearance between exit device and door jamb is usually between 1/2 and 3/4 inches. In order to meet such small dimensions, manufacturers developed no-cut strikes with dual fold-out keepers. No-cut strikes are made long and thin in order to provide a locking mechanism for both fold-out parts.

An example of a no-cut strike is the HES 9600 series. This strike was introduced in 2000 and can be used with most pullman latches having up to a 3/4 inch throw, 9600 strikes meet ANSI/BHMA A151.31 Grade one specifications and are UL 1034 burglary listed. Exterior dimensions of the HES 9600 strike are 1 3/4" wied by 3/4" thick by 9 inches high. A continuous duty solenoid can be field selectable from 12 to 24VDC. 9600 strikes can be set for fail safe or fail secure functions. A similar HES 9400 series electric strike is made to accept latches with up to a 1/2 inch throw. Elliptical mounting holes contained in HES 9400 and 9600 strikes allow for horizontal adjustment. Always make sure that door operates properly before installation to prevent undue pressure on electric strike parts.

Adams Rite has recently introduced a 9800 series of exit devices which use a rotating starwheel instead of a pullman latch. The starwheel interlocks with the strike plate, providing additional security against jamb spreading. As a compliment to the Adams-Rite 9800 series exit device, HES has designed a new 9800 series no-cut strike designed to operate with the starwheel design. Spacers are provided to fill any gap between strike and exit device. HES 9800 strikes can operate with with 12 VDC or 24 VDC power. HES is now part of the Assa Abloy Electronic Security Hardware Group.

A second example is no-cut strikes made by Trine. Axion 4800 and 4850 models are specifically designed for use with pullman latches. Trine Axion 4800 will accept pullman latches with up to a 3/4 inch throw, while the Axion 4850 will accept latch throws of 1/2 inch. A Trine Axiom 4801 model is designed to operate with Corbin Russwin and Yale devices equipped with a square bolt. Trine states that Axion latches have been tested to over one and one half million plus cycles. Oval mounting holes provide preliminary mounting adjustment while a patented anchoring system allows drilling of holes into the door jamb for permanent mounting.

The following manufacturers offer no-cut surface mounted electric strikes:

Assa Abloy Electronic Security Hardware:



RCI: (A dormaKaba Group Company)

Rofu: www.ROFU.COM        




Von Duprin: (An Allegion Brand)