Hydraulic Hose Color Codes, Ferrules, and Skiving Basics

Hydraulic hose is central to many systems, from mobile equipment to machinery that lifts, pushes, steers, or actuates heavy loads. The hose assembly has to match pressure, movement, impulse cycles, routing, and the fitting style at each end.

Three topics often appear together in hose work: color coding, ferrules, and skiving. Each one affects identification or assembly quality in a different way.

Color Coding in Hydraulic Circuits

Color coding can be used in hydraulic circuit schematics to identify flows and pressures during design. This does not necessarily mean the physical hose cover has to be that color.

The same hose family may be used in several parts of a hydraulic system. The circuit drawing may use standardized colors to help engineers and technicians understand pressure lines, return lines, pilot lines, drain lines, or other flow paths.

Hose Laylines and Pressure Families

Some hose manufacturers use color-coded laylines to identify constant-pressure hose families. These laylines can help distinguish hoses rated for different working pressures.

Many constant-pressure hoses are built around ISO 18752 performance definitions. Hose grade and type can indicate temperature capability, impulse cycle rating, pressure level, and bend behavior. The layline should be checked along with the actual hose specification, not used as the only identifier.

One-Piece and Two-Piece Hose Fittings

One-piece hose fittings have the ferrule already attached to the hose tail. This helps keep the collar aligned and ensures the ferrule and fitting are paired as a matched assembly. One-piece fittings are common in field maintenance and basic applications where quick assembly is helpful.

Two-piece hose fittings use a separate ferrule and hose stem. They provide more flexibility when matching 1SN, 2SN, multi-spiral, and other hose constructions to the application. They are often used where pressure, vibration, or pressure surges require more careful hose-to-fitting selection.

Ferrules and Manufacturer Matching

The ferrule is not a generic sleeve. It has to match the hose tail, hose construction, crimp specification, and manufacturer system. Mixing hose, ferrule, and fitting components from different systems can increase the chance of leaks or failure.

Two common ferrule styles are skive and non-skive. A skive ferrule has rounded teeth that grip the wire reinforcement after the hose cover is removed. A non-skive ferrule has sharper serrations that bite through the hose cover.

Skiving and Non-Skiving

Skiving removes the outer cover at the hose end so the ferrule can contact the reinforcement at the correct depth and length. Proper skiving is normally done with a skiving machine, not a knife or improvised tool.

Some high-pressure assemblies may also require internal skiving so the hose tail seats correctly. Non-skive assemblies leave the cover in place and rely on the ferrule design to bite through the cover during crimping.

The correct choice depends on the hose family, fitting style, pressure rating, and crimp data. Always match the hose, fitting, ferrule, and assembly procedure as a system.