Hydraulic hoses are most often divided into two varieties. One is considered braided and the other is considered spiral hose. Steel wire braid for hose is intertwined on a mandrill using a twine machine with multiple arms. These arms rotate in conjunction to lay wire braid. The wire braiding process is repeated for a second wire braid when desired.
The tightness and diameter of the steel wire braid determines the pressure capacity and flexibility of the wire braided hose. The number or wires (one or two) are also what help to define a wire braided hose. These hoses include SAE 100R1, SAE 100R2, SAE 100R16 and SAE 100R17 hydraulic hose.
For steel spiral hoses, there is no braiding involved and instead steel wire coils wrapped one on top of the other in sections usually no more than 50 feet long standard. These steel spirals can number either 4 or 6 depending on the pressure rating and flexibility required by the end user. Steel spiral hydraulic hose have a much higher pressure rating and are often classified as SAE 100R12, SAE 100R15, and 4SH hydraulic hose.