The basic bite type fitting was first developed in Europe in the early 1930s.

The Ferulok fitting was later developed by Parker-Hannifin and introduced to the U.S. market in the mid-1940s. The Ferulok fitting design utilizes a combination of proven European features, coupled with many innovative product improvements instituted by Parker Hannifin.

Today, the Ferulok fitting design and performance capabilities far exceed the strict requirements of SAE and military standards. The Ferulok fitting is a flareless fitting that consists of a body, a one-piece precision machined ferrule, and a nut. On assembly, the ferrule "bites" into the outer surface of the tube with sufficient strength to hold the tube against pressure, without significant distortion of the inside tube diameter. The ferrule also forms a pressure seal against the fitting body. Ferulok fittings allow the fitting assembler to visually inspect the bite quality, thus significantly minimizing the risk of improper assembly and related service problems. Ferulok fittings are especially suitable for use with tube wall thicknesses ranging from medium to extra heavy.

Ferulok’s robust construction and proven sealing characteristics have gained it worldwide popularity in diverse markets and applications. Ferulok fittings are routinely used in markets, such as: Machine tools, chemical, military, oil refineries, paper making, thermoplastics processing, etc.