The 3G114 mortice deadlock offers excellent protection against all common forms of attack including force, drilling, manipulation and hacksaw. This lock has a 14mm bolt. Tested to BS3621 1980 for Thief Resistant Locks (current edition is 2004) The 5 lever mechanism generates in excess of 1,000 key variations and is suitable for securing both domestic and industrial/commerical main entrance doors. This is the Chubb Lock that coined the phrase Chubb Lock.