Adhesive, also known as glue, cement, mucilage, or paste is any non metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation.
The use of adhesives offers many advantages over binding techniques such as sewing, mechanical fastening, thermal bonding, etc. These include the ability to bind different materials together, to distribute stress more efficiently across the joint, the cost effectiveness of an easily mechanized process, an improvement in aesthetic design, and increased design flexibility.
Thread-locking fluid or threadlocker is a thin, single-component adhesive, applied to the threads of fasteners such as screws and bolts to prevent loosening, leakage, and corrosion.
Thread-locking fluid may be applied before or after assembly, depending on the type. Threadlockers are available in varieties of "permanent", "removable", and "low-strength" formulas. Many brands color-code the container and the fluid itself to indicate the degree of permanency.
