Hose for Hydraulic Presses and Machine Tools

Pressure per millimetre of outside diameter. This body is rated 104 MPa (1,040 bar) on a 7.2 mm outside diameter at the 3 mm code, while a four-spiral 4SP at 3/8 inch is rated 44.5 MPa (445 bar) on a 22.2 mm outside diameter. Above roughly 500 bar the resin hose is the only practical body.

Because one layer reaches about 350 bar on a resin tube and two layers reach 1,040 bar. The table states the layer count explicitly, which matters: a single-layer R7 ordered by mistake would be running at a third of the pressure the circuit needs.

The smallest code has a 3.5 mm inside diameter and a 7.2 mm outside diameter, rated 104 MPa working (1,040 bar, 15,084 psi) with 260 MPa (2,600 bar) minimum burst. Minimum bend radius is 60 mm.

The largest code has a 6.3 mm inside diameter and an 11.5 mm outside diameter, with the same 104 MPa (1,040 bar) working pressure and 260 MPa burst. Bend radius rises to 85 mm, so the routing budget grows with the bore, not the pressure.

3 mm or 5 mm, depending on the cylinder displacement: a clamp that strokes a few millimetres takes the 3 mm code at a 60 mm bend, while a larger clamp needs the 5 mm code at 70 mm. All three codes share the 1,040 bar rating.

Price follows the bore and the fittings: 3.5 mm inside diameter at 7.2 mm outside on the smallest code, 6.3 mm inside at 11.5 mm outside on the largest, and each takes its own ferrule. A 1,040 bar assembly is quoted per piece rather than per metre, so send the circuit pressure and the end types for a firm figure.

Because the joint is the weakest part of a small-bore high-pressure circuit. A ferrule set for a rubber hose cuts a nylon core or leaves it unbonded, and at 104 MPa the leak appears within days. Every assembly here is built with the matching fitting system and proof-tested.

Because 60 mm is the minimum at 3 mm bore, and a resin core has no spare wall to resist ovalising at the limit. Lay the line out at 75 mm and it runs; clamp it at exactly 60 mm with a fitting at an angle and the clamp circuit starts responding slowly.

It is what the table states: 260 MPa burst against 104 MPa working. That is lower than the 4.0x on our lower-pressure ranges, which is deliberate for a compact resin body, and it is why a press line is specified on the working pressure and the relief setting rather than on the burst number.

YIBO, in Luohe, Henan, supplies the two-layer R7 range in 3 codes from 3 mm to 6 mm bore, all rated 104 MPa with 260 MPa burst, with matching fittings crimped and proof-tested in-house.