ISO 10317:2008

Overview - ISO 10317:2008 (Tapered roller bearings designation system)

ISO 10317:2008 defines a standardized designation system for metric tapered roller bearings manufactured in accordance with ISO 355. The standard covers designation formats for complete single-row and double-row bearings, bearings with flanged outer rings, and separate bearing subunits (inner subunit = inner ring, tapered rollers and cage; outer ring). ISO 10317:2008 applies only to bearings and parts that conform to ISO 355.

Key topics and requirements

• Designation structure: A multi-section code made up of groups of alphabetical and/or numerical symbols (sections 1–6). Each section identifies a specific attribute of the bearing.
• Subunit prefixes (section 1):
  • none = complete bearing
  • R = inner subunit (inner ring, rollers and cage)
  • L = outer ring
• Tapered roller designator (section 2): The letter T may be used optionally to indicate tapered roller bearings.
• Dimension series (section 3): Three-symbol series designation as defined in ISO 355 (dimension series links to bearing boundary dimensions).
• Bore size (section 4): Three numerals indicating nominal bore diameter in millimetres (leading zero for bores