Spiral Hydraulic Hose

Spiral reinforcement lays its wires in parallel helical layers, four or six of them, each wound opposite the one beneath, instead of interlacing them the way a braid does. Because wires within a layer never cross, they do not bear on one another under pressure, and load passes through the wall layer by layer rather than concentrating at every crossover.

Pressure rating is the obvious reason to reach for it; fatigue is the better one. Under repeated cycling the crossover points in a braid are where damage starts, while spiral layers share that load evenly and survive far more impulses at the same duty. SAE 100R12, 100R13 and 100R15 and the EN 856 4SP and 4SH types cover these constructions. The price is stiffness, weight and a larger bend radius.

Where it's specified

• Constant pressure cycling — presses and implement circuits stroking thousands of times a shift, where impulse life sets the service interval
• High-pressure pump lines — the layered wall keeps working where a two-braid hose is already at the edge of its rating
• Large bores — spiral construction holds pressure at diameters where braid becomes impractical
• Straight or gently swept runs — the trade for that strength is stiffness, so it belongs where there is room for a wide radius

Range and materials. Synthetic rubber inner tube, four or six layers of high-tensile steel wire and a tough abrasion-resistant cover, in the medium and large dash sizes that carry high-pressure flow. Ends crimp to JIC 37°, ORFS, SAE Code 61 and Code 62 flange and metric.

Ordering notes. Skive requirements differ by construction, so confirm whether the fitting calls for skived or no-skive hose before cutting, and crimp to the diameter published for that exact hose, fitting and die. Clamp long runs, since spiral hose is heavy enough to load its own end fittings, and give every bend more radius than you would allow on braid.