ISO 6626-3-2019 PDF
Name in English:
St ISO 6626-3-2019
Name in Russian:
Ст ISO 6626-3-2019
Original standard ISO 6626-3-2019 in PDF full version. Additional info + preview on request
Full title and description
Internal combustion engines — Piston rings — Part 3: Coil-spring-loaded oil control rings made of steel. Specifies essential dimensions, designation and related specification elements for coil-spring-loaded steel oil control piston rings (types SOR and SOV) intended for reciprocating internal combustion engines and analogous compressors.
Abstract
This International Standard defines the essential dimensional features, designation examples and relevant specification parameters for coil‑spring‑loaded oil control piston rings made of steel (SOR — R‑shaped groove, and SOV — V‑shaped groove). It applies to nominal ring diameters from 60 mm up to and including 160 mm and provides dimensional tables, slot and groove conventions, coil‑spring characteristics and surface/heat‑treatment notes needed to ensure interchangeability and consistent performance.
General information
- Status: Published (International Standard).
- Publication date: September 2019 (Edition 2, 2019).
- Publisher: International Organization for Standardization (ISO).
- ICS / categories: 43.060.10 (Engine block and internal components).
- Edition / version: Edition 2 (2019); replaces ISO 6626-3:2008.
- Number of pages: 26 (ISO published document page count).
Scope
Specifies the essential dimensions and related specification elements for coil‑spring‑loaded oil control rings made of steel (types SOR and SOV) with nominal diameters from 60 mm up to and including 160 mm for reciprocating internal combustion engines; the standard can also be applied to piston rings used in compressors under analogous conditions. The document focuses on interchangeability and dimensional definition rather than detailed performance testing.
Key topics and requirements
- Definition of piston ring types SOR (R‑shaped groove) and SOV (V‑shaped groove) and standard designation formats for ring identification.
- Essential dimensional parameters: nominal diameter, ring width (h), radial wall thickness (a), land widths and land angles, groove depths and slot geometries; dimensional tolerance tables for specified size ranges.
- Coil‑spring characteristics and acceptable spring types (designs, pitches, coil diameters and fitting guidance) to ensure correct ring expansion and oil control.
- Designation examples showing material, nitriding/coating notes, contact pressure class and other marking elements to standardize procurement and interchangeability.
- Notes on surface treatments (for example nitriding minimum case depths and coating classes), slot arrangements for oil evacuation and recommended visual inspection items.
Typical use and users
Primary users are piston‑ring manufacturers, internal combustion engine OEMs, compressor manufacturers, component suppliers and quality/inspection laboratories. The standard is used for design reference, production tooling, procurement specifications, dimensional inspection criteria and to ensure interchangeability between suppliers and engine builders.
Related standards
Part of the ISO piston‑ring family and typically used alongside other ISO piston‑ring standards, including the ISO 6626 series (parts for cast‑iron and narrow‑width rings), ISO 6621 (vocabulary, inspection and material specifications), ISO 6622/6623/6624/6625/6627 and national adoptions (BSI, DIN, etc.). See ISO 6626-1 (cast‑iron coil‑spring oil control rings) and ISO 6626-2 (narrow‑width cast‑iron types) for closely related parts.
Keywords
piston rings; oil control rings; coil‑spring‑loaded; steel rings; SOR; SOV; ring dimensions; nitriding; coil spring; ISO 6626; interchangeability; engine components.
FAQ
Q: What is this standard?
A: ISO 6626-3:2019 is an International Standard that specifies essential dimensions, designation and related elements for coil‑spring‑loaded oil control piston rings made of steel (types SOR and SOV).
Q: What does it cover?
A: It covers dimensional definitions, designation examples, coil‑spring characteristics, slot and groove conventions, surface‑treatment notes and tolerances for steel coil‑spring oil control rings with nominal diameters from 60 mm to 160 mm; it is intended for reciprocating IC engines and analogous compressors.
Q: Who typically uses it?
A: Ring manufacturers, engine OEMs, suppliers, component designers and inspection laboratories use the standard for production, procurement, specification and dimensional inspection to ensure interchangeability and consistent quality.
Q: Is it current or superseded?
A: The 2019 edition (Edition 2) is the published and effective edition. A revision work item (ISO/AWI 6626-3) has been registered and is under development to produce a future edition; until a new edition is published, ISO 6626-3:2019 remains the current standard.
Q: Is it part of a series?
A: Yes — ISO 6626-3 is part of the broader ISO piston‑ring standards family (ISO 6621, ISO 6622, ISO 6623, ISO 6624, ISO 6625, ISO 6626 series and ISO 6627). Related parts include ISO 6626-1 and ISO 6626-2 for cast‑iron and narrow‑width coil‑spring oil control rings.
Q: What are the key keywords?
A: piston rings; oil control rings; coil spring; steel; SOR; SOV; dimensions; nitriding; interchangeability; engine components.