Barbs grip onto tubing.

Metal hose fittings have better durability than plastic barbed hose fittings.

Also known as ball-seat hose nipples, these fittings consist of a barbed shaft with a rounded end that sits inside a female threaded nut. When mated with a male threaded fitting, the rounded end presses tightly against the inside of the male threads for a better seal than a single-piece fitting. Once assembled, insert the barbed end into hose and secure with a clamp or a crimp-on hose ferrule.

Couplings consist of a plug and a socket that connect and disconnect quickly. Use them if you need frequent access to a line. They are designed for coolant applications up to 200 psi. Also known as coolant-line mold couplings.