Maintenance, inspection, hydraulics and equipment finance

Hydraulics and Fittings

These pages cover the numbers behind small hydraulic systems: the force and speed of a cylinder from bore, rod and pressure, the hose inside diameter a flow needs, JIC and AN fitting dash sizes with their threads, and ISO viscosity grades. Results come from your inputs and the published formulas and tables named on each page. Pressure ratings, hose construction and fluid choice belong to the maker’s data.

Tools in this group

  • Hydraulic Cylinder Force Calculator — Enter the bore, rod diameter and pressure to get the push force on extend and the pull force on retract; add flow and stroke for speed, oil volume and time.
  • Hydraulic Hose Size Chart — See every dash size with its inside diameter in inches and millimeters, or enter your flow and a target velocity to find the smallest hose that fits.
  • Hydraulic Oil Viscosity Chart — Choose an ISO VG grade to see its midpoint viscosity and limits at 40 degrees C, or type a viscosity to see which grade limits it falls in.
  • JIC Fittings Chart — Pick a dash size for its tube outside diameter and 37 degree flare thread, or type a measured thread such as 9/16-18 to find the dash size.