This British Standard specifies performance requirements and test
methods for a thief resistant mechanically operated single-point lock
assembly (including locking plates, fixing screws, fitting instructions,
cylinders and protective furniture where appropriate) that:
a) incorporates a lock conforming to BS EN 12209 field of door
application grades A, B, C, D, E, F or J, i.e. a lock that can always
be unlocked from the inside without a key thereby only allowing
keyless egress; and
b) is used in doors, window doors and entrance doors in buildings.
This standard does not cover thief resistant lock assemblies that only
allow egress using a removable key, or lock assemblies that provide a
secure (no egress) mode in addition to keyless egress.
NOTE 1 Thief resistant lock assemblies that only allow egress using a key
or assemblies that provide a secure (no egress) mode in addition to keyless
egress are specified in separate standards, BS 3621 and BS 10621
(respectively), because they are sufficiently different in terms of what they
offer for means of escape (from fire) and security.
NOTE 2 It is possible that lock assemblies conforming to this standard
are not suitable for use on doors constructed from certain types of
material, e.g. plastic or aluminium. The marking on the packaging of the
lock assembly will provide this information in accordance with 9.2.
NOTE 3 A lock or latch assembly conforming to this standard can
be included as part of an exit device that conforms to BS EN 179
or BS EN 1125.