Loctite (play on the words "lock tight") is an American company founded in 1956 as American Sealants Company (renamed in 1963 to Loctite Corporation), which is primarily engaged in the manufacture of bonding and sealing chemicals.

The Loctite company was acquired in 1997 by the German group Henkel "Henkel (company)"). Metal adhesives are also included under the Loctite[1] brand, which are used to secure screws and as liquid sealants.