1-1/4 Inch Hydraulic Hose | Sizes, Models & Specifications

1-1/4 inch — dash 20, 31.4–33.0 mm bore — sits in the heavy end of the range. It is used where flow is measured in hundreds of litres per minute and the hose run is long enough that pressure drop, not burst strength, decides the bore.

1-1/4 Inch Hydraulic Hose: Pressure Rating by Construction

1SNBraided, 1 wire6.3 MPa (63 bar)2SNBraided, 2 wire10.5 MPa (105 bar)4SPSpiral, 4 wire21.0 MPa (210 bar)4SHSpiral, 4 wire32.5 MPa (325 bar)

Four constructions are produced in the 1-1/4 inch bore. Working pressure is the continuous rating at 30–60 °C with mineral oil; burst pressure is the minimum before rupture (typically 4× working pressure).

Nominal bore 31.4–33.0 mm, outside diameter 44.8 mm (1SN), minimum bend radius 420 mm, weight 1.17 kg/m (1SN).

Where 1-1/4 Inch Hydraulic Hose Is Used

• Mining dump trucks and loaders — Hoist and steering circuits on 90–240 tonne trucks, generally 4SH with code 62 flanges.
• Large hydraulic presses — Main ram supply lines on forging and stamping presses running at 300 bar continuously.
• Shipyard and port equipment — Ship loaders, unloaders and heavy winches where long runs make low velocity essential.
• Hydroelectric and dam equipment — Gate and turbine control systems, often in fire-resistant or water-glycol compatible constructions.

How to Choose the Right Construction

Braided hose at this bore is limited to 6.3 MPa (1SN) or 10.5 MPa (2SN) — essentially return and low-pressure lines. Anything above 150 bar should be 4SP (21 MPa) and anything above 300 bar needs 4SH (32.5 MPa). Because 1-1/4 inch assemblies are expensive, getting the pressure class right at the specification stage saves a full re-hose later.

Fittings for 1-1/4 Inch Hose

Code 62 split flanges are standard above 300 bar, with BSPP 1-1/4", JIC 1-5/8-12 and ORFS 1-11/16-12 as threaded alternatives. Allow extra length for the flange sweep when measuring.

Frequently Asked Questions

What dash size is 1-1/4 inch hose?

Dash 20. Model codes appear as 1SN-20, 4SP-20 and 4SH-20.

How much flow can 1-1/4 inch hose carry?

About 285 L/min at 6 m/s, which covers the main circuits of most mining and port equipment.

Why is 1-1/4 inch hose so much heavier?

1.17 kg/m for 1SN and around 2.8 kg/m for 4SH. The steel spiral layers add mass quickly at this bore, so plan supports and lifting points accordingly.

Tell us the working pressure, flow rate, fluid and fitting type, and YIBO will confirm the exact model, bend radius and lead time for your 1-1/4 inch hose. Samples are available for approval before volume production.