Nominal width, inner diameter and fill ratio
Protective hoses are designated by a nominal width (NW) that roughly matches the inner diameter. Add up the outer diameters of all cables, multiply by 1.3 to 1.5 for movement and pulling, and pick the next NW above that. A hose chosen too wide rattles and chafes internally; one chosen too tight makes pulling in almost impossible and sharply increases bending force.


