# ISO 3601: O-ring tolerances, surface and storage | Oringaero

Source: https://oringaero.fr/en/normes.html

## ISO 3601-1 — Dimensions and tolerances

ISO 3601-1:2012 covers the inside diameter, the cross-section and their tolerances. The catalogue drawings apply class A (annex A).

[Official ISO reference ↗](https://www.iso.org/fr/standard/58043.html) · The 2012 edition has a corrigendum and a 2019 amendment; check the edition required in the order.

## ISO 3601-3 — Surface imperfections

ISO 3601-3:2005 and its amendment 1:2018 define acceptance criteria for surface imperfections. Limits depend on the type of imperfection, the cross-section and the grade selected.

GradeUse
N | General purposeS | Special
CSCritical service

Dimensional class A does not determine the surface-quality grade. Catalogue O-rings are supplied to grade N per ISO 3601-3; grades S and CS are available on request.

Visual inspection may cover flash, parting-line offset, tears, flow marks, non-fills and inclusions. Numerical limits must come from the applicable standard and the specification.

[ISO 3601-3](https://www.iso.org/standard/40409.html) · [Amendment 2018](https://www.iso.org/standard/73527.html)

## Storage of unfitted parts

NF L 17-104 covers storage periods; NF L 17-103 covers packaging and storage conditions. The table below reproduces the values of the extract provided, whose notes a and b are not fully available.

Group | Families in the list | Before deliveryBefore fitting

II | NBR | 3 years8 years

III | CR, EPDM | 4 years10 years

IV | VMQ, FVMQ | 5 years (b)12 years (b)

V | FPM / FKM | 5 years (b)15 years (b)

These periods are not cumulative. They are neither a service life after fitting nor a shelf-life guarantee for the delivered product. Confirm the notes, manufacturing date, storage conditions and contract requirements before use.

[AFNOR notice — NF L 17-104](https://norminfo.afnor.org/norme/nf-l17-104/serie-aerospatiale-materiaux-caoutchouc-produits-non-montes-durees-limites-de-stockage/129437)

## To specify in your request

Dimensions, material, quantity, fluid, temperature range, pressure, static or dynamic use, surface grade and required documents.

[Prepare my request](https://oringaero.fr/en/devis.html)