Hoses

What is a hydraulic hose?

A hydraulic hose is a flexible, reinforced hose designed to carry hydraulic fluid under high pressure between the components of a hydraulic system, such as pumps, valves, cylinders, and motors. Unlike rigid steel tubes, hoses can bend, flex, and move, which makes them ideal for connecting parts that move relative to each other, absorbing vibration and routing fluid around tight spaces on machinery.

Most hydraulic hoses are made up of three main layers:

• Inner tube - the innermost layer that carries the fluid, usually made from oil-resistant synthetic rubber such as nitrile, designed to be compatible with hydraulic oils and to prevent leakage
• Reinforcement - one or more layers of high-tensile steel wire or textile, either braided or spiral-wound, that give the hose its pressure strength. The more layers and the stronger the reinforcement, the higher the pressure the hose can handle
• Outer cover - a tough synthetic rubber layer that protects the reinforcement from abrasion, weather, ozone, UV, oil, and chemicals

Key features:

• High pressure capability - depending on type and size, hydraulic hoses can handle working pressures from a few bar up to well over 400 bar
• Flexibility - hoses bend and move with the machine, making routing easier and allowing for moving parts
• Vibration absorption - hoses help absorb vibration and pressure pulses, protecting fittings and components
• Wide size range - available from small hoses of around ¼ inch inside diameter up to large hoses of 2 inches and beyond
• Clear identification - a printed layline along the hose shows the brand, standard, size, working pressure, and manufacturing date
• Temperature resistance - standard hoses typically work from around -40 Deg C to +100 Deg C, with special hoses available for higher temperatures

In simple terms, a hydraulic hose is the flexible, high-strength pipeline that carries the pressurized fluid that powers a hydraulic machine.

Why are hydraulic hoses essential?

Hydraulic hoses are essential because they connect every part of a hydraulic system together. Without them, the pressurised fluid that drives cylinders, motors, and other components could not reach where it is needed. Hoses must work reliably under high pressure, constant flexing, vibration, and harsh environments, so choosing and maintaining the right hose is critical to the performance and safety of the machine. 

Their main benefits are:

• Power transmission - hoses carry pressurised fluid efficiently, allowing machines to lift, push, dig, steer, and drive
• Flexibility and movement - they connect components that move, such as loader arms, booms, cylinders, and steering systems
• Vibration and shock absorption - hoses absorb vibration and pressure surges better than rigid tubes, protecting fittings, pumps, and valves
• Easy routing - hoses can be bent around obstacles and through tight spaces where rigid pipes would be difficult to fit
• Simple installation and replacement - hose assemblies can be made up to the required length and replaced quickly when worn
• Wide choice - many pressure ratings, sizes, and constructions are available to suit almost any application
• Durability - good-quality hoses resist abrasion, weather, ozone, oil, and temperature changes 
• Safety - correctly chosen and assembled hoses safely contain high pressures, protecting operators and workers

These qualities make hydraulic hoses important in a wide range of industries and equipment, including: 

• Agricultural machinery - tractors, front loaders, trailers, sprays, balers, harvesters, and implements
• Construction machinery - excavators, loaders, dumpers, cranes, telehandlers, and piling rigs
• Industrial machinery - presses, injection moulding machines, machine tools, and hydraulic power units
• Material handling - forklifts, lifting platforms, scissor lifts, and conveyors
• Mining and quarrying - drilling rigs, crushers, haul trucks, and underground equipment
• Forestry - harvesters, forwarders, cranes, and log splitters
• Commercial vehicles - tipper trucks, refuse vehicles, tail lifts, and lorry-mounted cranes
• Marine and offshore - winches, steering systems, deck machinery, and offshore equipment
• Waste and recycling - compactors, balers, and shredders

The main types of hydraulic hoses

Hydraulic hoses are usually grouped by their reinforcement type, pressure rating, and the standard they are made to.

Wire braided hoses:

• 1SN hoses - one braid of high-tensile steel wire, suitable for medium pressure applications such as return lines, lighter equipment, and low pressure circuits
• 2SN hoses - two braids of high-tensile steel wire, giving much higher pressure ratings. They are one of the most widely used hydraulic hoses, suitable for most agricultural, construction, and industrial  applications
• 1SC and 2SC compact hoses - braided hoses with a thinner, more compact construction, giving a smaller outside diameter and tighter bend radius than standard SN hoses, ideal for tight spaces
• SAE100R16 and 100R17 hoses - compact braided hoses with tight bend radii, and with 100R17 offering a constant working pressure across several sizes

Spiral wire hoses:

• 4SP hoses - four spiral layers of steel wire for high-pressure applications, commonly in smaller and medium sizes
• 4SH hoses - four spiral layers designed for very high pressures in larger sizes
• R12, R13, and R15 hoses - heavy-duty spiral hoses for high and very high pressure applications with severe pressure surges, such as excavators, mining machinery, and heavy hydraulic systems

Textile and low pressure hoses:

• Textile reinforced hoses - reinforced with textile braids, used for low pressure lines, return lines, and pilot lines
• Suction hoses - reinforced with a wire helix to stop them collapsing under suction, used on pump inlet lines
• Return line hoses - designed for low-pressure return lines back to the tank

Thermoplastic hoses:

• SAE100R7 and 100R8 hoses - thermoplastic hoses with synthetic fibre reinforcement, which are lightweight and non-conductive. They are often used on aerial platforms, utility vehicles, and forklifts

Special hoses:

• SAE100R7 and 100R8 hoses - thermoplastic hoses with synthetic fibre reinforcement, which are lightweight and non-conductive. They are often used on aerial platforms, utility vehicles and forklifts

Special hoses:

• High temperature hoses - for applications with hot fluids or hot surroundings
• Abrasion-resistant hoses - with tough covers that offer much greater abrasion resistance than standard covers
• Low temperature hoses - for cold climates and arctic conditions
• Biodegradable fluid hoses - compatible with environmentally friendly hydraulic oils
• Twin hoses - two hoses joined side by side, used for implements and attachments
• MSHA-approved and flame-resistant hoses - for mining and applications with fire risks

How to choose the right hydraulic hose?

Choosing the right hydraulic hose is essential for safety and performance. A widely used approach is the STAMPED method, which stands for size, temperature, application, media, pressure, ends, and delivery. Work through these points in order:

• Size - choose the correct inside diameter to give the required flow without excessive pressure loss or fluid velocity. Hose sizes are given in inches, dash sizes, or DN sizes, for example ½ inch, -8, or DN12
• Temperature - check that the hose can handle both the fluid temperature and the surrounding temperature. High temperatures can shorten hose life significantly
• Application - consider how the hose will be used, including flexing, bending, vibration, routing, movement, abrasion, and space available. Check the minimum bend radius and allow enough length for movement
• Media - make sure the inner tube is compatible with the fluid, whether mineral oil, biodegradable oil, water glycol, fuel, or another fluid
• Pressure - choose a hose with a maximum working pressure equal to or greater than the system’s maximum pressure, including pressure spikes. Never use a hose above its rated working pressure
• Ends - choose the correct fittings for the connections, and make sure they are compatible with the shoe type and crimped to the manufacturer’s specifications
• Delivery - consider the flow rate, volume, and any special requirements, such as testing, cleanliness, or certification

Other points to consider:

• Hose standard - choosing a hose made to a recognised standard, such as EN 853 2SN, ensures predictable performance and makes it easier to find replacements
• Reinforcement type - braided hoses offer good flexibility for medium and high pressures, while spiral hoses are better for very high pressures and severe pressure surges
• Outside diameter - check that the hose fits the available splice, clamps, and hose protection
• Cover performance - consider abrasion-resistant covers for hoses that rub or are exposed to rough conditions
• Matching fittings - always use fittings designed for the specific hose. Mixing hoses and fittings from different manufacturers is not recommended unless the combination is approved
• Quality and brand - choose hoses from reputable manufacturers and suppliers, as poor-quality hoses can fail early and pose serious safety risks

Essential references and hydraulic hose ranges

Hydraulic hoses are made to international standards that define their construction, pressure ratings, and dimensions. Understanding these standards and size systems makes it easy to identify the right hose.

Common hose sizes:

• 1/4 inch - dash size -4, DN6, about 6.4mm inside diameter
• 5/16 inch - dash size -5, DN8, about 7.9mm inside diameter
• 3/8 inch - dash size -6, DN10, about 9.5mm inside diameter
• 1/2 inch - dash size -8, DN12, about 12.7mm inside diameter
• 5/8 inch - dash size -10, DN16, about 15.9mm inside diameter
• 3/4 inch - dash size -12, DN19 or DN20, about 19mm inside diameter
• 1 inch - dash size -16, DN25, about 25.4mm inside diameter
• 1 1/4 inch - dash size -20, DN31 or DN32, about 31.8mm inside diameter
• 1 1/2 inch - dash size -24, DN38 or DN40, about 38.1mm inside diameter
• 2 inch - dash size -32, DN51 or DN 50, about 50.8mm inside diameter

Typical minimum working pressures for EN 853 2SN hoses:

• 1/4 inch (DN6) - 400 bar
• 5/16 inch (DN8) - 350 bar
• 3/8 inch (DN10) - 330 bar
• 1/2 inch (DN12) - 275 bar
• 5/8 inch (DN16) - 250 bar
• 3/4 inch (DN19) - 215 bar
• 1 inch (DN25) - 165 bar
• 1 1/4 inch (DN31) - 125 bar
• 1 1/2 inch (DN38) - 90 bar
• 2 inch (DN51) - 80 bar

Typical minimum working pressures for EN 853 1SN hoses:

• 1/4 inch (DN6) - 225 bar
• 3/8 inch (DN10) - 180 bar
• 1/2 inch (DN12) - 160 bar
• 5/8 inch (DN16) - 130 bar
• 3/4 inch (DN19) - 105 bar
• 1 inch (DN25) - 88 bar

These figures are the minimums set by the standard, and many manufacturers’ hoses exceed them, so always check the manufacturer’s data and the pressure printed on the hose layline. Hydraulic hoses are usually designed with a safety factor of 4:1, meaning the minimum burst pressure is four times the working pressure. 

FAQ - all you need to know about hydraulic hoses

What does 2SN mean?

2SN refers to the EN 853 2SN standard, which describes a hose with two braids of high-tensile steel wire reinforcement and a thin, abrasion-resistant cover. It is one of the most commonly used hydraulic hoses for medium and high-pressure applications.

What is the difference between 1SN and 2SN hose?

1SN hose has one steel wire braid, while 2SN hose has two. This gives 2SN hose a much higher pressure rating for the same size.

What is the difference between braided and spiral hoses?

Braided hoses have criss-crossed wire reinforcement and are more flexible, suiting medium to high pressures. Spiral hoses have wires wound in layers and handle higher pressures and severe pressure surges better.

How do I measure a hydraulic hose?

Hydraulic hoses are sized by inside diameter. If the layline is worn, measure the outside diameter and compare it with the manufacturer’s data.

Can I mix hoses and fittings from different brands?

It is not recommended unless the combination is approved by the manufacturer, as fittings are designed and tested to match specific hoses.

How long do hydraulic hoses last?

Service life depends on pressure, temperature, flexing, abrasion, environment, and maintenance. Hoses should be inspected regularly and replaced when they show signs of wear or damage. Many users also replace hoses after a set number of years, regardless of appearance. 

What are the signs that a hose needs replacing?

Signs include leaks, cracks, abrasion through the cover, exposed reinforcement, bulging, kinks, stiffness, damaged or corroded fittings, and hoses that have been crushed or pulled.

Why do hydraulic hoses fail?

Common causes include abrasion, incorrect routing, bending too tightly, twisting, excessive pressure, high temperatures, incompatible fluids, poor-quality crimping, and age.

Is a hydraulic hose leak dangerous?

Yes, fluid escaping under high pressure, even from a pinhole, can penetrate the skin and cause serious injury. Never check for leaks with your hands, and seek urgent medical help if fluid is injected into the skin.

How should hydraulic hoses be stored?

Store hoses in a cool, dry, dark place away from sunlight, ozone sources such as electric motors, chemicals, and heat. Keep the ends capped and avoid tight coils or heavy weights on top.

How do I find the right hose?

Check the layline on the existing hose for the standard, size, and pressure. If it is worn, measure the hose and fittings.