Thread lockers and retainers are used to render threaded fasteners immovable. They are used mainly with devices that are subject to transverse and axial loads that may lead to vibrational loosening. There are two basic types of thread lockers and retainers: adhesives and sealants. Adhesives are organic or inorganic chemical compounds for joining compounds. Sealants are liquid compounds that prevent leaks and block the ingress of unwanted materials. Some thread lockers and retainers are compatible with materials made of ceramics, glass, concrete, masonry, metal, plastic, or wood. Others adhere to porous surfaces or composite materials. Products that can bond dissimilar substrates such as metal to rubber are also available.