Anti-thrust plate is Locksmith terminology for a flat device that is fitted to the external face of a door, overlapping the edge and covering the gap between the door and frame to prevent someone using an implement to tamper with the latch or bolt.
Because it overlaps the edge of the door, it can only be fitted to a pair of doors or a single door that opens outward.
For the same reason, if it is fitted to double doors that open inward, it cannot be fitted to the door that opens first.
Kickstop supplies high security Anti-Thrust Plates and very high security Anti-ThrustGuards and a complete list and description is provided below.
Anti-Thrust Devices:
to provide anti-jemmy protection for mortice deadlocks and latches
AT1UK , 2021UK, AT1EU, 2021EU, AT1OV, 2021OV
to provide anti-jemmy protection for mortice sashlocks
AT5, 2025
to provide anti-jemmy protection for cylinder rimlocks
AT6
to provide anti jemmy protection for single or double doors - with no keyway
AT1, AT2, AT4