3/4 Inch Hydraulic Hose | Sizes, Models & Specifications

3/4 inch — dash 12, 18.6–19.8 mm bore — is where spiral hose becomes the norm rather than the exception. It is the main pressure line on excavators in the 20–30 tonne class, on concrete pumps and on most heavy lifting equipment.

3/4 Inch Hydraulic Hose: Pressure Rating by Construction

1SNBraided, 1 wire10.5 MPa (105 bar)2SNBraided, 2 wire15.5 MPa (155 bar)4SPSpiral, 4 wire35.0 MPa (350 bar)4SHSpiral, 4 wire42.0 MPa (420 bar)

Four constructions are produced in the 3/4 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 18.6–19.8 mm, outside diameter 28.5 mm (1SN), minimum bend radius 240 mm, weight 0.66 kg/m (1SN).

Where 3/4 Inch Hydraulic Hose Is Used

• Excavators from 20 to 30 tonnes — Boom and arm circuits running at 300–350 bar, almost always 4SH or 4SP rather than braided hose.
• Concrete pump trucks — Delivery and boom cylinders, where high pressure combines with constant pulsing and vibration.
• Hydraulic presses and shears — The supply line between pump and valve block on workshop and scrap-yard equipment.
• Agricultural and forestry machines — Harvester heads and heavy loader arms that need a bore large enough to keep oil temperature under control.

How to Choose the Right Construction

This is one of the sizes where 4SH becomes practical, and it matters: 4SH gives 42 MPa against 35 MPa for 4SP in the same bore, with a slightly larger outside diameter. If your system runs at 350 bar or above, specify 4SH. Braided 1SN at 10.5 MPa is really only suitable for return and suction-side lines at this bore.

Fittings for 3/4 Inch Hose

3/4 inch hose is usually terminated with SAE code 61 or 62 flanges, BSPP (3/4"), JIC 37° (1-1/16-12) or ORFS (1-3/16-12). Flange connections are preferred above 300 bar because they resist torque and vibration better than threaded joints.

Frequently Asked Questions

What is 3/4 inch hose in dash size?

Dash 12. The nominal bore is 19 mm, which is why the model codes read 1SN-12, 4SP-12 and 4SH-12.

4SP or 4SH for 3/4 inch?

4SP is rated 35 MPa, 4SH is rated 42 MPa. Choose 4SH when working pressure exceeds 350 bar or when the hose sees heavy impulse cycling.

How tight can 3/4 inch hose bend?

240 mm minimum bend radius for 1SN, around 280–350 mm for four-spiral constructions. Measure to the inside of the bend, not the centreline.

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 3/4 inch hose. Samples are available for approval before volume production.