The differences between tube bend and elbow

Although the words tube bend and elbow are often used as synonyms, there are still some differences between them.

Tube bend is a term for any offset of direction in the piping while elbow is an engineering term.

Elbow has limitations to angle, bend radius and size. Most angles are either 45 degree or 90 degree. All other offsets are specifically tube bends. And while elbows have sharp corners, bends never do. The most basic difference between a bend and an elbow is the radius of curvature. Bends have a radius more than twice the diameter, and elbows have a radius of curvature between one and two times the size of the pipe’s diameter. All elbows are bends, but not all bends are elbows.