BS 3621:2017

This standard BS 3621:2017 Lock assemblies operated by key from both the inside and outside of the door is classified in these ICS categories:

• 91.190 Building accessories
• 13.310 Protection against crime

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:

1. incorporates a lock conforming to BS EN 12209:2016 that can be locked from both sides with a key thereby only allowing key egress; and

2. is used in doors, window doors and entrance doors in buildings.

This standard does not cover thief-resistant lock assemblies that provide keyless egress, i.e. lock assemblies that can always be unlocked from the inside without the need for a key, or lock assemblies that provide a secure (no egress) mode in addition to keyless egress.

NOTE 1 Thief-resistant lock assemblies that provide keyless egress or assemblies that provide a secure (no egress) mode in addition to keyless egress are specified in BS 8621 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 might not be suitable for use on doors constructed from certain types of material, e.g. plastic or aluminium. See 9.2 , which specifies the information to be provided on the marking on the packaging of the lock assembly.