jail lock

plural jail locks

1. A kind of cast iron padlock.

   The outer, and inner entrance doors have jail locks.

   1887, Minnesota State Board of Corrections and Charities, Biennial Report of the State Board of Corrections and Charities

   4 more examples

   To prevent this and the possibility of scandal (which could happen on trumped up charges) a grated steel door with jail lock should be placed on this doorway.

   1927, New York Legislative Documents - Volume 20, page 343

   Also known as jail locks, Scandinavian padlocks were made from cast components, having a malleable iron body, shackle, and key.

   2007, Graham Pulford, High-Security Mechanical Locks: An Encyclopedic Reference, →ISBN

   An old jail lock hanging on the wall swayed back and forth.

   2009, Michael Norman, The Nearly Departed, →ISBN

   The locks to the doors must be the Scandinavian Jail Lock.

   2013, Robin Sterling, People and Things from the Cullman, Alabama Tribune 1877, →ISBN

   Synonyms: Scandinavian padlock

2. Used other than figuratively or idiomatically: see jail, lock.