Hydraulic hose construction and performance is covered by various national and international standards including ISO, BSI, hashtag#SAE, DIN, API and CETOP. 

SAE100 standards provides general, dimensional and performance specifications for the most common hoses used in hydraulic systems on mobile and stationary equipment. 

The majority of hydraulic machines are not exotic, and typically your standard SAE 100R1 or SAE 100R2 ("1-wire" and "2-wire" respectively) hoses are appropriate.

The SAE100 standard list is as follows:
#SAE100R1 #SAE100R2 #SAE100R3 #SAE100R4 #SAE100R5 #SAE100R6 #SAE100R7 #SAE100R8 #SAE100R12 #SAE100R13 #SAE100R14 #SAE100R15 #SAE100R16 #SAE100R17 #SAE100R18 #SAE100R19