Solenoid bolts are a type of locking mechanism appropriate for most doors. The name comes from the locking activation by use of a solenoid, a coil wound into a tightly packed helix. Solenoid bolts are electro-magnetic devices which can be manufactured to trigger both when switched on or switched off, depending on user choice, a function that acts as a fail-safe in the event of power failure. When activated, the bolt is forced into the strike, preventing the door from opening. Solenoid bolts are known, depending on product, to have a holding force of up to 1,000kg, making them an ideal choice for both private and commercial property. They are often used in high-security buildings, where the activation of an alarm can trigger the solenoid bolts to lock the premises down.
The Tate Colson deedlock monitored solenoid bolt is a standard and functional choice for distance locking. It comes with a power failure mode that triggers an unlock, which can be preferable in case of sudden power loss with people still in the building. They are dual monitored with a voltage of 12V DC and come competitively priced from easylocks.