ISO 3601-1 Seal: O-ring · Products: 709 ISO 3601-1 - Fluid power systems - O-rings - Part 1: Inside diameters, cross-sections, tolerances and designation codes O-rings of circular cross-section for seals in fluid power systems. ISO 3601-1:2012 specifies the inside diameter d1, the cross-section diameter d2, their tolerances and the size codes: codes 001–475 are the general industrial sizes (Tables 1–6, tolerance class A or B), codes A0018–E4000 the aerospace sizes (Tables 7–11).
