ISO 3601-1-2012 pdf free.Fluid power systems — O-rings — Part 1: Inside diameters, cross-sections,tolerances and designation codes.
This part of ISO 3601 specifies the inside diameters, cross-sections, tolerances and designation codes for 0-rings used in fluid power systems for general industrial and aerospace applications.
The dimensions and tolerances specified in this part of ISO 3601 are suitable for any elastomeric material, provided that suitable tooling is available.
NOTE The tooling most commonly available is based on 70 IRHD NBR shrinkage rates (see ISO 48). For materials that shrink differently from this standard NBR compound, a special mould can be required to maintain the mean diameters and the to4erance limits listed.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and 100 IRHD)
ISO 3601-3, Fluid power systems — 0-rings — Part 3: Quality acceptance criteria ISO 5598, Fluid power systems and components — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 apply.
4 Symbols
The following symbols are used in this part of ISO 3601:
— d1 0-ring inside diameter;
— d2 0-ring cross-section diameter.
6 Inside diameters, d1, cross-sections (section diameter), “2’ and tolerances
6.1 The combinations of inside diameters and cross-section diameters shall be chosen depending on the application:
from Tables 1 through 6 for general industrial applications;
– from Tables 7 through 11 for aerospace applications.
6.2 For industrial applications, two classes of inside diameter tolerances, class A and class B, are specified. The tolerance of class B 0-rings is based on Equation (A.1). Class A 0-rings have tighter inside diameter tolerances than class B 0-rings and are suitable for industrial or aerospace applications when the application or the housing require tighter tolerances. Class B 0-rings have dimensions and tolerances suitable for general-purpose applications. The inside diameter tolerances are based on Equation (A.1). For information, Figure 2 shows a graphical comparison of the inside-diameter tolerances for class A and class B 0-rings.
6.3 Cross-section tolerances for non-standard (custom) 0-rings for general industrial applications not listed in Tables 1 through 6 can be chosen from Table A.1. Tolerances for inside diameters for non-standard (custom) class A 0-rings are listed in Table A.2. Equation (A.1) can be used to calculate inside diameter tolerances for non-standard (custom) class B 0-rings.
In marginal cases, the compliance with the limits of the shape deviations and surface imperfections should be considered besides the dimensional tolerances. See ISO 3601-3.ISO 3601-1 pdf download.