Working pressure, wire counts, fitting styles, crimp specs — explained in plain English, so you know exactly what's on your machine and what should be. No jargon, no upsell, just how it works.
Pressure basics
Every hydraulic hose carries two numbers that matter:
Working pressure (WP) is what the hose is designed to run at, all day, every day — including the spikes your circuit throws at it when an attachment bites or a ram hits the end of its stroke.
Burst pressure is the catastrophic failure point — typically rated at 4× working pressure (the 4:1 safety factor). It exists so an occasional spike doesn't kill you. It is never the number you select hose on.
Heat, fluid type, bend radius and impulse cycling all chew into those ratings over time — which is why two identical-looking hoses can have very different jobs.
Rule one of hydraulics: the hose, the fitting and the crimp all have to meet the spec — together. Any one of the three out of spec and the assembly is only as good as a guess.
Hose construction
The wires are the reinforcement layers between the inner tube and the outer cover. More wire — and how it's wound — is what buys you pressure capability.
Steel wire braided in a criss-cross pattern. Flexible, compact and cost-effective — the workhorse construction on most machines.
Wire wound in flat spiral layers. Stiffer, tougher and built for serious pressure and constant impulse loading.
Quick reference
| Hose type | Construction | Typical working pressure* | Where you'll find it |
|---|---|---|---|
| R1AT | 1-wire braid | ≈ 725 – 3,265 PSI | Return lines, low-pressure circuits |
| R2AT | 2-wire braid | ≈ 1,300 – 5,800 PSI | General machine hydraulics — the everyday standard |
| 4SP | 4-wire spiral | ≈ 3,600 – 6,500 PSI | Pump lines, high-cycle earthmoving circuits |
| 4SH | 4-wire spiral | ≈ 4,200 – 6,100 PSI | Larger-bore high-pressure lines on heavy gear |
| R13 | Multi-spiral | 5,000 PSI constant | Constant high-pressure systems |
| R15 | 6-wire spiral | 6,000 PSI constant | Hammers, breakers & the hardest-working circuits |
| Jack / test hose | Thermoplastic or spiral | Up to 10,000 PSI | Porta-powers, jacking & pressure-test equipment |
Not sure which row you're in? Text a photo of the hose and its layline to 0488 229 981 and we'll tell you exactly what it is and what should replace it.
Reading the layline
The layline is the printing that runs along every hydraulic hose. Once you can read it, you can never be sold the wrong hose again.
MASTERHOSE · R2AT-08 · ½″ (12.7 MM) · WP 24.5 MPA (3,550 PSI) · SAE 100R2AT · EN 853 2SN
Who made it and the construction standard — here a 2-wire braided R2AT.
-08 means 8/16″ = ½″ inside diameter. Dash sizes count in sixteenths of an inch.
The continuous rating for this exact size — in MPa and PSI.
The SAE / EN specs the hose is built and tested to.
Fitting styles
The fitting matters as much as the hose — thread form and sealing style have to match the port exactly. The usual suspects:
The most common hydraulic end in Australia. Seals metal-to-metal on a 37° cone seat.
British parallel and taper threads — everywhere on older and European gear. Parallel seals on a cone or bonded washer; taper seals on the thread.
Flat face with an O-ring — excellent leak resistance under vibration. Common on newer earthmoving equipment.
Straight thread with an O-ring at the port face — standard port thread on many pumps and valves.
Split-flange connections for big-bore, high-pressure lines on pumps and travel motors. Code 62 is the high-pressure series.
24° cone (light and heavy series) and other metric forms on European and Asian machinery.
Golden rule: bring the old fitting, or text a clear photo of it. Threads that "nearly fit" are how ports get wrecked.
Matched systems
A crimped assembly is an engineered joint: the fitting's collar bites into the hose at a precise crimp diameter, published for that exact hose-and-fitting pair.
Cross-brand combinations generally have no published crimp spec and no test data. They might hold — but nobody has proven it, and the failure mode is the fitting letting go under pressure.
Code-matched systems like Masterhose are impulse (pulse) tested as complete assemblies — hose, fitting and crimp cycled at pressure hundreds of thousands of times — with spec sheets and crimp ranges published for every combination.
Assemblies cycled at rated pressure through hundreds of thousands of pulses before they earn the rating.
Every hose-and-fitting pair has a documented crimp diameter — we crimp to it, then verify it.
Ratings, standards and dimensions documented for every product we fit — ask and we'll show you.
Testing & compliance
There are two kinds of testing, and they answer different questions.
Pulse (impulse) testing is done by the manufacturer — cycling an assembly type at pressure hundreds of thousands of times to earn its rating. It proves the design.
Proof (hydrostatic) testing is done on the actual assembly you're about to fit — pressurising it with fluid to a set multiple of working pressure, holding it, and checking for leaks or distortion. It proves that specific hose.
For coal mines and quarries, Queensland's Recognised Standard 23 makes this matter: fluid power assemblies must be correctly built, identified, tracked, tested and certified — with records to back it up. See how VMECH builds to RS23 →
Read Recognised Standard 23 (PDF)
Product selection
Five letters cover almost every hose decision. Run through them before you order — or just tell us the answers and we'll spec it.
Inside diameter (dash size) and overall length — undersized hose runs hot and starves the circuit.
Fluid and ambient temps — heat is the #1 killer of hose covers and tubes.
Routing, bend radius, abrasion, flexing — where and how the hose actually lives.
What's inside: hydraulic oil, bio-oils, water-glycol, fuel — the tube must be compatible.
Maximum working pressure including spikes — matched to the hose's rating at that size.
FAQ
Working pressure is what the hose is designed to run at continuously; burst pressure is the catastrophic failure point, typically 4× working pressure (the 4:1 safety factor). Always select on working pressure — and make sure it covers your circuit's spikes, not just the gauge reading.
Depends on the bore: ¼″ R2AT is rated around 5,800 PSI, but by 1½″ it drops to roughly 1,300 PSI. Bigger bore, lower rating — always check the layline for your size.
High pressure plus high impulse: pump lines, hammers, breakers and hard-cycling circuits on earthmoving gear. R13 runs 5,000 PSI and R15 runs 6,000 PSI constant working pressure, and spiral construction shrugs off spikes that fatigue braided hose.
No — every hose-and-fitting pair has its own crimp spec, and cross-brand combos are generally untested. A mismatched crimp is the most common assembly failure. Code-matched systems exist precisely to close that gap.
Read the layline — type, dash size, working pressure and standard are all printed on the hose. Layline worn off? Text a photo of the hose and both fittings to 0488 229 981 and we'll identify it.
This page is general guidance only. Pressure ratings vary by manufacturer, size and standard — always confirm against the specific product's spec sheet, and never exceed the lowest-rated component in a circuit.
Text a photo of the hose, layline or fitting and we'll identify it, spec the replacement and quote it — usually within the hour.
