Choosing a hydraulic hose - pressure, bore, fitting?
A hydraulic hose is defined by six criteria, summarised as STAMPED: Size, Temperature, Application, Media, Pressure and Ends. Bore, pressure rating per EN 853 or SAE 100R, temperature range, fluid compatibility and the right fitting together make a safe, durable line.
View hydraulic hosesHow do I choose a hydraulic hose with the STAMPED method?
The STAMPED method sums up the six criteria that uniquely define a hydraulic hose: Size (bore and length), Temperature (operating temperature), Application (use and routing), Media (fluid), Pressure (working pressure) and Ends (fittings). Only when all six match is the line safe.
| Letter | Criterion | What to check |
|---|---|---|
| S - Size | bore and length | bore from flow velocity, length including bends |
| T - Temperature | operating temperature | fluid and ambient temperature, continuous and peak values |
| A - Application | use | routing, movement, abrasion, indoor or outdoor use |
| M - Media | fluid | hydraulic oil, emulsion or special fluid, inner tube compatibility |
| P - Pressure | working pressure | maximum working pressure incl. spikes, safety factor to burst pressure |
| E - Ends | fittings | fitting type, thread or seal cone, crimped connection |
For matching system planning see the article Hydraulic power unit on sizing pump, tank and pressure.
How do I set pressure rating and bore?
The working pressure must stay permanently below the hose's allowed working pressure. Between working and burst pressure sits a safety factor, for hydraulic hoses typically 4:1. The construction per EN 853 or SAE 100R sets the pressure rating through the number and type of wire layers.
| Type | Reinforcement | Typical pressure range |
|---|---|---|
| EN 853 1SN / SAE 100R1 | one wire braid | medium pressure, depending on bore |
| EN 853 2SN / SAE 100R2 | two wire braids | high pressure, depending on bore |
| SAE 100R12 | four spiral plies | very high pressure, impulse loads |
| SAE 100R13 | multi-layer spiral | highest pressure, heavy hydraulics |
The bore follows from the flow rate and the allowed flow velocity. In pressure lines 3 to 6 m/s is common, in suction lines far less. Too small a bore raises pressure loss and heat build-up.
What matters for temperature, fitting and bend radius?
Temperature and fluid must suit the hose inner tube, the fitting must suit the coupling, and the minimum bend radius must not be undercut. These three points decide tightness and service life just as much as pressure does.
Operating temperature and fluid must suit the inner layer, allow for peak values.
ViewThe fitting is part of the hose assembly: fitting and hose are crimped with the matching die, and only released combinations are permitted. A wrong crimp diameter or an unsuitable fitting leads to leakage or blow-off.
Frequently asked questions
What does the STAMPED method stand for on a hydraulic hose?
STAMPED stands for Size (bore and length), Temperature, Application (use), Media (fluid), Pressure and Ends (fittings). These six criteria fully define the right hose and are worked through in order before the selection is made.
How are working pressure and burst pressure related?
The allowed working pressure is the pressure for continuous operation. The burst pressure sits well above it, for hydraulic hoses typically with a safety factor of 4:1. Burst pressure is only a test limit and must never be used as an operating reference.
How do I choose the right bore?
The bore follows from the flow rate and the allowed flow velocity. In pressure lines 3 to 6 m/s is common. Too small a bore raises pressure loss and heat build-up, while too large a bore makes the line needlessly expensive.
The right hydraulic hose for your system
Bore, pressure rating per EN 853 / SAE 100R and fitting - we help you select by STAMPED.
Reviewed
Content reviewed by hydraulics specialists.
Wide range
Hoses to EN 853 and SAE 100R in stock.
Assembly
Hose lines crimped to length correctly.
Expert advice
Personal advice on hose selection.