ISO 6621-5:2020
Internal combustion engines — Piston rings — Part 5: Quality requirements
Internal combustion engines — Piston rings — Part 5: Quality requirements
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 13
- Дата публикации:
- 27 января 2020 г.
- Издание:
- ISO IS 6621 edition 4 version 1
- ICS:
- 43.060.10
This document specifies quality aspects that can be defined but that are not normally found on a drawing specification. It covers the following: — single‑piece piston rings of grey cast iron or steel; — multi‑piece piston rings (oil control rings) consisting of cast iron parts and spring components; and — single‑piece and multi‑piece oil control rings of steel, i.e. oil control rings in the form of strip steel components or steel segments (rails) with spring expander components. In addition to specifying some of the limits of acceptance relating to inspection measuring principles (covered by ISO 6621‑2), this document also covers those features for which no recognized quantitative measurement procedures exist and which are only checked visually with normal eyesight (glasses if worn normally) and without magnification. Such features (superficial defects) are additional to the standard tolerances of ring width, radial wall thickness and closed gap. This document does not establish acceptable quality levels (AQL), it being left to manufacturer and customer to decide the appropriate levels jointly. In this case, the recommendations of ISO 2859‑1 are followed. This document specifies the quality requirements of piston rings for reciprocating internal combustion engines for road vehicles and other applications. It is applicable to all such rings of a nominal diameter from 30 mm up to and including 200 mm.
Abstract
Overview - ISO 6621-5:2020 (Piston rings - Quality requirements)
ISO 6621-5:2020 defines quality requirements for piston rings used in reciprocating internal combustion engines (road vehicles and other applications). It covers visual and measurable quality aspects that are typically not detailed on engineering drawings. The standard applies to single‑piece piston rings (grey cast iron or steel), multi‑piece oil control rings (cast iron parts with spring components), and steel oil control rings (strip steel components or rails with expander springs) with nominal diameters from 30 mm to 200 mm.
Key technical topics and requirements
- Scope of defects: Specifies permissible visible and superficial defects (porosity, sand inclusions, pores, scratches, indentations, depressions, chipping, burrs and cracks) and classifies them for inspection.
- Visual inspection rules: Visual checks are performed without magnification by inspectors with normal eyesight (glasses allowed). Many features covered are assessed only visually because no standardized quantitative measurement exists.
- Material and ring types: Applies to grey cast iron and steel single‑piece rings, multi‑piece oil control rings, and steel segment/rail oil control rings with expander springs.
- Limits and acceptance: Quantifies commonly encountered casting and machining defects, permissible sizes/depths and spacing for many defect types (see clauses on pores, scratches, indentations and burrs). No cracks are permissible in base material.
- Edge and burr control: Defines acceptable burr size/orientation and permitted material removal during deburring.
- Coatings and surface treatments: Notes special considerations for plated, nitrided and PVD‑coated surfaces (e.g., restrictions on indentations and cracking).
- Sampling and AQL: The standard does not set Acceptable Quality Levels (AQL). Manufacturer and customer must agree on AQL (recommendation: ISO 2859-1 sampling procedures).
- Related inspection measurements: Some inspection measuring principles are handled in ISO 6621‑2.
Practical applications and who uses ISO 6621-5
- Piston ring manufacturers - define internal quality control limits and production acceptance criteria.
- OEMs and suppliers - include as a contractual reference for incoming inspection, supplier approvals and disputes.
- Quality engineers and inspectors - apply visual acceptance and sampling rules during production and incoming goods inspections.
- Design and application engineers - use the standard alongside ISO 6621‑3/‑4 when selecting ring types and understanding manufacturing tolerances.
- Laboratories and auditors - reference for audit checks, failure analysis and coating/heat‑treatment verification.
Related standards
- ISO 6621‑1 - Vocabulary
- ISO 6621‑2 - Inspection measuring principles
- ISO 6621 series (Parts 3, 4, etc.) - ring selection and dimensional data
- ISO 2859‑1 - Sampling procedures and AQL
Keywords: ISO 6621-5, piston rings quality requirements, visible defects, oil control rings, casting defects, inspection, AQL, piston ring inspection.
Технические детали
- Технический комитет
- ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
- SKU
- ISO 6621-5:2020
Похожие стандарты
Стандарты, упомянутые в описании
BS ISO 28591:2017
ДействующийSequential sampling plans for inspection by attributes.
ISO 6621-2:2020
ДействующийInternal combustion engines — Piston rings — Part 2: Inspection measuring principles
Overview - ISO 6621-2:2020 (Piston rings - Inspection measuring principles) ISO 6621-2:2020 specifies the measuring principles used to inspect piston rings for reciprocating internal combustion engin…
ISO 6621-5:2013
ОтменёнInternal combustion engines — Piston rings — Part 5: Quality requirements
ISO 6621-3:2000
ОтменёнInternal combustion engines — Piston rings — Part 3: Material specifications
ISO 6621-1:2018
ДействующийInternal combustion engines — Piston rings — Part 1: Vocabulary
Overview ISO 6621-1:2018 provides a standardized vocabulary for piston rings used in reciprocating internal combustion engines and for compressors operating under analogous conditions. The document d…