The document specifies the dimensions of grooves for use with o-rings according to 'EN-standards for aerospace appplications: - radial sealing: rod or bore mounted o-rings; - axial sealing: internal or external pressure source.
DIN EN 3748:2002 history
2002DIN EN 3748:2002 Aerospace series - O-ring grooves - Dimensions; German and English version EN 3748:2001