-J-

 

jackscrew

n. a threaded rod used for centering and balancing a vault door & frame in position during installation

 

jamb

n. the vertical components of a door frame

 

jiggered finish

n. a surface adorned with overlapping concentric circles

 

jimmy proof

adj. pertaining to a lock having a bolt which interlocks with its strike

 

JIS

abb. Japanese Industrial Standard

 

jumbo cylinder

n. a rim or mortise cylinder of 1-1/2" diameter

This listing of the Locksmith Dictionary is courtesy of