Hydraulic Hose Fittings & Sizing: Dash Sizes, Ends & Crimping
Every hydraulic hose order comes down to the same five answers — size, pressure, ends, length, application. Get those from the machine, not from memory, and the assembly fits the first time. Here's how each one works.
Dash Sizes
Hydraulic hose and fittings are sized in dashes: sixteenths of an inch of inside diameter. A -08 hose is 1/2" ID; a -12 is 3/4". The hose layline prints the dash size and SAE spec — when replacing, read the layline rather than measuring a swollen old hose.
SAE 100R Constructions
| Type | Construction | Typical use |
|---|---|---|
| 100R1 / R17 (1-wire) | One wire braid | Return lines, low-pressure circuits |
| 100R2 / R16 (2-wire) | Two wire braids | General high-pressure hydraulics |
| 100R12 / R13 / R15 (spiral) | 4–6 spiral wire | High-impulse: excavators, presses, frac |
| 100R7 / R8 | Thermoplastic | Lifts, non-conductive service |
Match working pressure at the hose size you need — a 2-wire that's rated 5,800 psi at -04 is only 3,100 psi at -12. Impulse-heavy machines (anything with a breaker or cycling cylinder) justify spiral hose even where braid nominally covers the pressure.
Fitting Ends
JIC 37° flare dominates North American equipment; ORFS where zero-leak matters; NPT for ports and plumbing; metric DIN/BSP on European and Asian machines. Identify both ends before ordering — our thread ID guide shows how — and note orientation (straight, 45°, 90°) and any drop lengths on bent-tube ends.
Why Crimp Specs Matter
A hydraulic assembly is only as good as its crimp: correct fitting series for the hose, correct die, correct crimp diameter measured and recorded. We crimp metric and standard hydraulic hose in-house to manufacturer crimp specs, pressure-test, and tag every assembly — most builds go out same day. Field-made assemblies with mismatched fittings are the leading cause of fitting blow-off injuries.
Measuring Replacement Length
Measure overall length including fittings, seat-to-seat, with the machine in its neutral position, and add slack for flexing circuits — hose shortens up to 4% under pressure. Photograph the routing before removal; it answers half the questions.
Same-Day Hydraulic Assemblies
Send dash size, SAE type or working pressure, both ends, and length through the quote form at the top of this page, visit our hydraulic hose page, or call (979) 233-6223 — quotes in 1–2 business hours, most builds same day.