ISO 6621-1 INTERNATIONAL STANDARD Second edition 2007-11-01 Internal combustion engines — Piston rings — Part 1: Vocabulary Moteurs combustion interne — Segments de piston — Partie 1: Vocabulaire Reference number ISO 6621-1:2007(E) © ISO 2007 `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO 6621-1:2007(E) PDF disclaimer This PDF file may contain embedded typefaces In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy The ISO Central Secretariat accepts no liability in this area Adobe is a trademark of Adobe Systems Incorporated `,,```,,,,````-`-`,,`,,`,`,,` - Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing Every care has been taken to ensure that the file is suitable for use by ISO member bodies In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below COPYRIGHT PROTECTED DOCUMENT © ISO 2007 All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) Contents Page Foreword iv Introduction v Scope Normative references Piston ring classification 4.1 4.2 4.3 4.4 4.5 Piston ring types Cross section configuration Peripheral surface configuration Edge configuration Coated, plated and nitrided surfaces configuration Joint configuration 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Piston ring nomenclature Free (unstressed) ring Closed ring Assembled ring in closed condition Edges, surfaces and faces Chamfered edges 10 Scraper ring 10 Oil control ring 11 6.1 6.2 6.3 6.4 Terms and definitions 13 Types of piston ring 13 Physical characteristics of rings 14 Piston part 15 Measuring devices 15 `,,```,,,,````-`-`,,`,,`,`,,` - Annex A (informative) List of equivalent terms in English, French, Russian, German, Spanish, Portuguese, Italian and Japanese 16 Alphabetical index 22 Bibliography 29 iii © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO 6621-1:2007(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights ISO shall not be held responsible for identifying any or all such patent rights ISO 6621-1 was prepared by Technical Committee ISO/TC 22, Road vehicles This second edition cancels and replaces the first edition (ISO 6621-1:1986) which has been technically revised ISO 6621 consists of the following parts, under the general title Internal combustion engines — Piston rings: ⎯ Part 1: Vocabulary ⎯ Part 2: Inspection measuring principles ⎯ Part 3: Material specifications ⎯ Part 4: General specifications ⎯ Part 5: Quality requirements iv Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale `,,```,,,,````-`-`,,`,,`,`,,` - The main task of technical committees is to prepare International Standards Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote ISO 6621-1:2007(E) Introduction ISO 6621 is one of a series of International Standards dealing with piston rings for reciprocating internal combustion engines Others are ISO 6622 [1],[2], ISO 6623 [3], ISO 6624 [4],[5],[6],[7], ISO 6625 [8], ISO 6626 [9],[10],[11] and ISO 6627 [12] `,,```,,,,````-`-`,,`,,`,`,,` - v © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale INTERNATIONAL STANDARD ISO 6621-1:2007(E) Internal combustion engines — Piston rings — Part 1: Vocabulary Scope This part of ISO 6621 defines the most commonly used terms for piston rings These terms designate either types of piston rings or certain characteristics and phenomena of piston rings The terms and definitions in this part of ISO 6621 apply to piston rings for reciprocating internal combustion engines They may also be used for piston rings of compressors working under analogous conditions NOTE Further terms and definitions covering measuring principles are given in ISO 6621-2 NOTE In addition to terms given in the three official ISO languages (English, French and Russian), this part of ISO 6621 gives the equivalent terms in the German, Spanish, Portuguese, Italian and Japanese languages However, only the terms given in the official languages can be considered as ISO terms These have been included at the request of Technical Committee ISO/TC 22 and are published under the responsibility of the member bodies for Germany (DIN), Spain (AENOR), Portugal (IPQ), Italy (UNI) and Japan (JIS) Normative references The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies ISO 286-1, Geometrical product specifications (GPS) — ISO code system for tolerances of linear sizes — Part 1: Basis of tolerances, deviations and fits `,,```,,,,````-`-`,,`,,`,`,,` - © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO 6621-1:2007(E) Piston ring classification `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) 4.1 Piston ring types Cross section configuration The more common cross section configurations in general use are shown in Table Combinations of configurations listed in Tables to along with those in Table are shown as “common features” in the relevant ISO Standard referenced in each table Table — Cross section configuration Type Cross section Relevant International Standard 6622-1 Rectangular ring 6622-2 6624-1 Keystone ring 6624-3 6624-2 Half keystone ring 6624-4 Scraper ring (stepped) 6623 Napier ring (undercut stepped) 6623 Slotted oil control ring 6625 Double-bevelled-edge oil control ring 6625 Bevelled-edge oil control ring 6625 6626 Coil-spring-loaded slotted oil control ring 6626-2 6626 Coil-spring-loaded double-bevelled-edge oil control ring 6626-2 `,,```,,,,````-`-`,,`,,`,`,,` - © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO 6621-1:2007(E) Table (continued) Type Cross section Relevant International Standard 6626 Coil-spring-loaded bevelled-edge oil control ring 6626-2 Steel oil control ring with V-groove 6626-3 Expander/segment oil control ring 6627 4.2 Peripheral surface configuration The more common peripheral surface configurations in general use are shown in Table Table — Peripheral surface configuration Configuration Cross section Relevant International Standard 6622-1/6622-2 6623 Peripheral surface straight faced 6624-1/6624-2 6624-3/6624-4 6622-1/6622-2 6624-1/6624-2 Peripheral surface barrel faced 6624-3/6624-4 6622-1/6622-2 Peripheral surface asymmetrical barrel faced `,,```,,,,````-`-`,,`,,`,`,,` - 6624-1/6624-3 6622-1/6622-2 6623/6624-1 Peripheral surface taper faced 6624-3 6622-1/6622-2 Peripheral surface taper faced partially cylindrical machined or lapped 6623/6624-1 6624-3 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS arc-boutement tourné en forme suivant une came jeu la coupe épaisseur du revêtement segment racleur d’huile ressort hélicoïdale butting cam turned closed gap coating layer thickness coil-spring-loaded oil control ring маслосъёмное кольцо Dachfasensegment racleur со встречной фаской Ölabstreifring régulateur d’huile chanfreiné symétrique 16 Not for Resale Berührung der Stossflächen Schichtdicke Stossspiel маслосъёмное кольцо Ölabstreifring mit с витым Schlauchfeder расширителем толщина покрытия замкнутый тепловой зазор обточенный по копиру formgedreht смыкание замка ballige Lauffläche bevelled-edge oil control ring бочкообразность по рабочей поверхности bombé sur la périphérie Balligkeit German barrel on peripheral surface с бочкообразной рабочей поверхностью Russian face bombée French barrel-faced English Abaulamento na face de contato Face abaulada Portuguese Espessura da camada de revestimento/ enchimento Folga entre pontas Torneamento de forma Batimento de pontas segmento de engrase Anel de óleo com mola expansor helicoidal helicoidal espesor del recubrimiento ajuste de puntas torneado de forma contacto de las puntas segmento de engrase Anel de óleo de chanfros simétricos de patines com mola helicoidal achaflanados simétricos periferia bombeada bombeado Spanish 合い口すきま カム旋削加工 合い口突き当たり Anello raccogliolio caricato molla elicoidale リング きオイルコントロール コイルエキスパンダ付 Spessore rivestimento コーティング厚さ Gioco al taglio Tornito di forma (con camma) Contatto delle estremità dell’anello ベベルオイルコントロ Anello raccogliolio smussi convergenti ールリング 外周面バレル バレルフェース Japanese Bombatura sul diametro esterno Bombatura Italian List of equivalent terms in English, French, Russian, German, Spanish, Portuguese, Italian and Japanese `,,```,,,,````-`-`,,`,,`,`,,` - Annex A (informative) ISO 6621-1:2007(E) © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale encastré arêtes intérieures chanfreinées arêtes intérieures et périphériques chanfreinées chanfrein sur le diamètre intérieur, flanc inférieur (type torsion négative) inlaid inside edges chamfered inside and peripheral edges chamfered internal bevel bottom (negative twist type) voilage helix/wind Innenkantenbruch Füllung кольцо с внутренней нижней фаской (обратное скручивание) Innenfase an Unterflanke (negative Vertwistung) Innen- und с фасками на внутренней и рабочей Aussenkantenbruch поверхностях с внутренними фасками с заполненной канавкой смещение стыкования Stossversatz Conformaỗóo tộrmica Anel semi-trapezoidal Face de contato totalmente revestida Planicidade no estado livre Forza diametrale Smusso sul diametro interno inferiore (tipo a torsione negativa) Spigoli interni ed esterni smussati Spigoli interni smussati Rivestimento esterno in cava Elica / ondulazione Formatura a caldo Anello semitrapezoidale Superficie periferica interamente rivestita Planarità dell’anello libero Apertura libera efficace `,,```,,,,````-`-`,,`,,`,`,,` - Chanfro de torỗóo interior inferior (torỗóo negativa) chaflỏn interior, inferior (torsional negativo) Arestas interiores e exteriores chanfradas Arestas interiores chanfradas Incrustado cantos interiores y exteriores biselados cantos interiores biselados inserto/cajetin desalineación axial de Hélice las puntas abertura térmica thermisch gespannt heat-formed mis en forme chaud с горячей формовкой half keystone ring с покрытием рабочей поверчности segmento semitrapecial sur toute la face fully-faced Ebenheit im planicidad en estado unbelasteten Zustand libre отклонение от плскости кольца в свободном состоянии abertura libre efectiva Abertura livre efetiva tatsächliche Maulweite раствор замка минус тепловой зазор einseitiger Trapezring planéité l’état libre free flatness Forca diametral Anello raccogliolio segmento de engrase Anel de óleo de chanfros paralelos com smussi paralleli de patines mola helicoidal achaflanados paralelos carga diametral Veja plano de referência ver : plano de referencia segment semi-trapèze кольцо трапецевидное одностороннее ouverture libre effective effective free gap маслосъёмное кольцо Gleichfasenс параллельными Ölabstreifring фасками Diametralkraft Piano di riferimento (Superfície de referência) (superficie de referencia) Italian Anello di compressione Portuguese Anel de compressão segmento de compresión Spanish totalmente recubierto segment racleur régulateur d’huile chanfreiné parallèle double-bevelled oil control ring диаметральная сила Messebene Verdichtungsring German Laufflächenbeschichtung force diamétrale diametral force see reference plane voir plan de référence базовая поверхность (для измерений) (datum surface) компрессионное кольцо Russian segment de compression French compression ring English ル（逆ねじれタイプ） 下面インターナルベベ 内外周面取り 内周面取り インレイド ヘリックス ヒート・ホーム グ ハーフキーストンリン 外周全面 平面ひずみ 有効フリーギャップ ントロールリング ダブルベベルオイルコ 直径張力 データム面 グ コンプレッションリン Japanese ISO 6621-1:2007(E) 17 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS embrèvement sur le diamètre intérieur, flanc supérieur (type torsion positive) coupe coupe avec encoche intérieure coupe avec encoche frontale angle du trapèze segment trapèze décalage des lèvres hauteur de lèvre étanchéité la boite lumière module d’élasticité joint joint with internal notch joint with side notch keystone angle keystone ring land offset land width light tightness modulus of elasticity embrèvement sur le diamètre intérieur, flanc inférieur (type torsion négative) chanfrein sur le diamètre intérieur, flanc supérieur (type torsion positive) (positive twist type) internal step top (negative twist type) internal step bottom (positive twist type) internal bevel top French 18 Not for Resale Laufsteghöhe модуль упругости Elastizitätsmodul Corte com entalhe interior Corte Rebaixo interior superior (torỗóo positiva) Vedaỗóo luz Espessura da face de contato Desalinhamento das faces Anel trapezodial Ãngulo trapézio プ） ップ（逆ねじれタイ 下面インターナルステ ル（正ねじれタイプ） 上面インターナルベベ Japanese キーストンリング キーストン角度 側面回り止め 内周回り止め 回り止め形状 Modulo di elasticità Tenuta alla luce Altezza pattino 縦弾性係数 ライトタイトネス 当たり幅 Disassamento pattino 当たり面段差 Anello trapezoidale Angolo del trapezio Gioco al taglio arresto frontale Gioco al taglio arresto interno Estremità Gradino sul diametro 上面インターナルステ interno superiore (tipo ップ（正ねじれタイ a torsione positiva) プ） Rebaixo interior inferior Gradino sul diametro (torỗóo negativa) interno inferiore (tipo a torsione negativa) múdulo de elasticidad Módulo de elasticidade estanqueidad a la luz altura del patin de roce desalineación de los patines segmento trapecial Trapezring Laufstegversatz ángulo trapecial Italian Smusso sul diametro Chanfro de torỗóo interior superior (torỗóo interno superiore (tipo a torsione positiva) positiva) Portuguese entalla para fijo lateral Corte com entalhe lateral entalla para fijo interior corte (torsional positivo) escalón interior, superior (torsional negativo) escalón interior, inferior (torsional positivo) chaflán interior, superior Spanish Trapezwinkel Stoss mit Flankensicherung плотность прилегания Lichtspaltdichtheit высота перемычки смещение перемычки кольцо трапецевидное двустороннее угол трапеции (трапецивидности) замок с боковой фиксацией Stoss mit Innensicherung замок с внутренней фиксацией Innenwinkel an Oberflanke (positive Vertwistung) кольцо с внутренней верхней выточкой (прямое скручивание) Stoss Innenwinkel an Unterflanke (negative Vertwistung) кольцо с внутренней нижней выточкой (обратное скручивание) замок Innenfase an Oberflanke (positive Vertwistung) German кольцо с внутренней верхней фаской (прямое скручивание) Russian `,,```,,,,````-`-`,,`,,`,`,,` - English ISO 6621-1:2007(E) © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale segment racleur d’huile ovalité arêtes périphériques chanfreinées surface périphériques рабочая поверхность кольца (portée du segment) oil-control ring ovality or circularity peripheral edges chamfered peripheral surface Schieflage Ovalität oder Kreisförmigkeit répartition de pression эпюра рапределения давления pressure pattern Superficie di scorrimento segment rectangulaire прямоугольное кольцо Rechteckring rectangular ring Segmento rectangular Anel regangular Plano de referência Plano de referencia Messebene базовая поверхность plan de référence reference plane Anello rettangolare Piano di riferimento Spessore radiale Espessura radial Espesor radial radiale Wanddicke épaisseur radiale radial wall thickness радиальная толщина Rientranza punte Anello (segmento) Distribuiỗóo da pressóo Distribuzione della pressione Ponto de deflexão Anel de pistão Passagem de luz difusa Trafilamento luce puntinato o sfumato Face de contato Spigoli esterni smussati Ovalità Anello raccogliolio Obliquità Diametro nominale dell’anello Anello raschiaolio (Napier) superficie periferica conica Radialdruckverteilung Distribucioón de la presión Punto de flexion Stosseinfall прогиб стыкования protusion point deflection Segmento de pistón Luz difusa Kolbenring Lichtpunkte oder Lichtschimmer Face de Contacto Arestas exteriores chanfradas Ovalizaỗóo Ovalidad Canto exteriores biselados Anel de úleo Inclinaỗóo Diõmetro nominal Anel Anel raspador Napier com face de contacto cơnica Segmento control de aceite Inclinación Diametro nominal del segmento поршневое кольцо segment de piston piston ring мерцающий просвет pointe d’épingle ou lumière irisée Lauffläche с наружными фасками Laufflächenkantenbruch овальность pin point or burry light (ring face) коробление obliquité obliqueness Nenndurchmesser маслосъёмное кольцо Ölabstreifring номинальный диаметр кольца Segmento rascador de a periferia cónica Abstreifring mit konischer Lauffläche und hinterstochener Eindrehung скребковое кольцо с подвнутренней канавкой и конической рабочей поверхностью Anello raschiaolio (Napier) Anel raspador “Napier” segmento rascador de uña Abstreifring mit hinterstochener Eindrehung скребковое кольцо с подвнутренней Italian Anel de mỳltiplas peỗas Anello multipezzo Portuguese segmento de varias piezas Spanish mehrteiliger Ring German составное кольцо (многоелементное) Russian nominal ring diameter diamètre nominal du segment segment bec d’aigle, face conique segment bec d’aigle Napier ring Napier ring, taperfaced segment multi-pièces French multi-piece ring English レクタンギュラリング 基準面 厚さ 面圧分布 ン ポイントデフレクショ ピストンリング かすかな断続的な光 外周面 外周面取り 度 オーバリティ又は真円 ング オイルコントロールリ 傾き リング呼び径 リング テーパフェースナピア ナピアリング 組合せリング Japanese ISO 6621-1:2007(E) `,,```,,,,````-`-`,,`,,`,`,,` - 19 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS 20 Not for Resale cylindrique force tangentielle segment conique straight-faced tangential force taper-faced ring segment trapèze face conique segment racleur d’huile avec lumières slotted oil-control ring taper-faced keystone ring Segmento de una sola pieza einteiliger Ring segment mono-pièce single-piece ring Anel de uma só peỗa Semi incrustado Segmento cúnico trapecial Anello conicit periferica Carico tangenziale Anel trapezoidal com Anello trapezoidale a face de contacto cônica superficie periferica conica Anel com face de contacto cơnica Segmento cónico Rechteckring mit konischer Lauffläche ( Minutenring ) Trapezring mit konischer Laufflọche Forỗa tangencial Carga tangencial Tangentialkraft тангенциальная (касательная) сила кольцо трапецевидное двустороннее с конической рабочей поверхностью Anello raccogliolio feritoie scarico olio Anello monopezzo Riporto esterno in semi-cava Face de contacto plana Superficie di contatto cilindrica Cara recta zylindrische Lauffläche С цилиндрической рабочей поверхностью маслосъёмное кольцо Ölschlitzс прорезями Ölabstreifring одноэлементное кольцо Anello raschiaolio (con gradino) Altezza dell’anello Cava del pistone Calibro circolare Italian Anel raspador com face Anello raschiaolio de contacto cônica (con gradino) a superficie periferica conica Anel raspador Altura Anel Canaleta Calibre para Anel Portuguese Segmento de engrase Anel de óleo com ventanas fendas Semi inserto einseitige Füllung semi-encastré semi-inlaid с полузаполненной канавкой Segmento cónico rascador Alture de segmento Abstreifring mit konischer Lauffläche Ringhưhe Ranura de pistón scraper ring segment racleur mixte скребковое кольцо (с (stepped), taper-faced (épaulé droit) portée канавкой) с конической рабочей conique поверхностью высота кольца Ringnut Calibre para segmento Spanish Segmento rascador hauteur du segment ring width поршневая канавка Kontrollring German Abstreifring gorge de segment ring groove кольцевой калибр Russian scraper ring (stepped) segment racleur mixte скребковое кольцо (с канавкой) (épaulé droit) bague de contrôle ring gauge French `,,```,,,,````-`-`,,`,,`,`,,` - English トンリング テーパフェースキース テーパフェースリング 接線張力 ストレートフェース ールリング 窓付きオイルコントロ シングルピースリング セミインレイド ーパリング テーパフェーススクレ スクレーパリング リング幅 リング溝 リングゲージ Japanese ISO 6621-1:2007(E) © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Russian ouverture libre totale torsion segment non-revêtue inégalité voilage ligne témoin twist uncoated ring unevenness wind © ISO 2007 – All rights reserved Not for Resale witness line линия контакта Tragspiegel смещение стыкования Stossversatz (axial) Unebenheit Linea de testimonio Giro Ondulación Segmento sin recubrimiento unbeschichteter Ring кольцо без покрытия неровность Torsión / torsional Abertura libre Maulweite Vertwistung Perfil cónico Spanish Winkligkeit (Zylindrizität , Konizität) German скручивание размер замка кольца в свободном состоянии cône sur la périphérie конусность по рабочей поверхности total free gap taper on periphery French `,,```,,,,````-`-`,,`,,`,`,,` - English Linha testemunha Desvio das pontas (empeno) Ondulaỗóo Anel sem revestimento Torỗóo Albertura livre total Conicidade da face de contacto Portuguese Japanese 合口部の軸方向段差 側面うねり 無処理リング ツイスト 自由合い口すきま Testimonio di contatto 当たり確認線 Svergolamento assiale Ondulazione Anello non rivestito Torsionale Apertura totale anello libero Conicità sulla periferia 外周面テーパ Italian ISO 6621-1:2007(E) 21 ISO 6621-1:2007(E) Alphabetical index Characteristic/Term Assembly radial thickness Symbol a11 ISO Reference 6627 Clause/Subclause 5.7 6622-1/6622-2 Asymmetrical barrel-faced rings (see rectangular and keystone rings) 6624-1/6624-3 6621-2 Barrel face (barrel on peripheral surface) t2, t3 6622-1/6622-2 6624-1 ff until 6624-4 6622-1/6622-2 Barrel-faced rings, see rectangular, keystone and half keystone rings 6624-1 ff until 6624-4 6625 Bevelled-edge oil-control ring Bridge length 6626 w2 6626-1 5.7 6626/6626-2/6626-3 4.2/5.2/5.5 Burrs 6621-5 Casting skin 6621-5 4.5 Cavities 6621-5 4.2 Chamfering 6621-4 10 Chipping 6621-5 4.4 Chromium beads (nodules) 6621-5 4.5 Chromium plating hardness 6621-4 10.1 Classification of piston rings 6621-1 6621-1/6621-4 5.2/7.3 Coating configurations 6621-1 4.4 Coating thickness 6621-4/6622 ff 10 Coating thickness tolerance 6621-4 10 6621-1/6626/6626-2 5.7/5.1 6626 5.1 6621-1/6626 5.1/5.2 6621-1/6626/6626-2 5.7/7 Coil-spring-loaded double-bevelled oil-control rings 6626/6626-2 3.3/4.3 Coil-spring-loaded oil-control rings 6626/6626-2/6626-3 Coil-spring-loaded slotted oil-control rings 6626/6626-2 Closed gap Coil spring diameter s1 d7 Coil spring types Coil spring excursion Coil spring groove diameter Contact pressure f1 d14 po 6626/6626-2 6/7 6626-3/6627 5.7/8 `,,```,,,,````-`-`,,`,,`,`,,` - 22 Organization for Standardization Copyright International Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) Symbol ISO Reference Clause/Subclause 6626/6626-2 7.4./6.4 6627 8.2 Correction of Ft and Fd values 6621-4 7.4 Cracks 6621-5 4.3 Cross sectional configuration 6621-1 6625 4.1-Table 6626/6626-2 4.1-Table / 5.2 Cylinder bore 6621-1 5.2 Datum surface (reference plane) 6621-1 6.4 Deburring 6621-5 4.4 Definitions (terms and definitions) 6621-1 Deposits (dirt) 6621-5 4.5 Depressions (dents) 6621-5 4.3 Designation of piston rings 6621-4 6621-2/6621-4 4.2/7.4 Contact pressure classes Cutter diameter Diametral force d5 Fd 6622-1 ff until 6625 Discoloration 6621-5 Double-bevelled oil control ring 6625 Drag marks 6621-5 4.4.1 4.3 6621-1/6621-5/6623 Edge chamfers (KA, KI) 6624-1/6624-2/6625 Edge features/configurations 6621-1 4.3 6622-2 5.7 6624-3/6624-4 5.1/5.2 Edges (defects) 6621-5 4.4 Edges (CR, SC, nitrided) 6621-4 10 Expander/segment oil control rings 6627 Edge radius outside, inside hx, hy Expander radial thickness a9 6627 5.7 Expander width h9 6627 5.7 External land depth a17 6627 5.7 6621-4 10.4 6621-2 4.2 6621-5 7.3 6621-4 7.4 Ferroxide treatment Flatness of side faces (uneveness) Force correction factors 6622-1 ff until 6626-2 Free gap (effective) 6621-1 6.2 23 © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS `,,```,,,,````-`-`,,`,,`,`,,` - Characteristic/Term Not for Resale ISO 6621-1:2007(E) Characteristic/Term Symbol ISO Reference Clause/Subclause 6621-1/6621-2 5.1/4.2 6626/6626-2 3.2 Gap corners 6621-5 4.4 Gap edges chamfered 6621-4 10 Gas porosity 6621-5 4.2 6621-1 5.7 Free gap (total) m Groove depth a4 Groove depth and bridge a13 6626/6626-2/6626-3 6621-1 5.7 6626/6626-2/6626-3 Groove root diameter (piston) 6621-1 5.3 Groove root radius (piston) 6621-1 5.3 Groove width (piston) 6621-1 5.3 Half keystone rings 6624-2/6624-4 Hardness (material) 6621-3 Table Hardness test indentations 6621-5 4.3 Heat set behaviour 6626/6626-2 5.4/6.4 Heat set resistance 6621-5 5.2 (Table 10) Helix (wind) 6621-2/6621-5 4.2/7.4 6621-1/6622-1/6623 Inside chamfered edges, KI Inside rounded edges 6624-1/6624-2/6625 hy Inside surfaces 6622-2 5.7 6624-3/6624-4 5.1/5.2 6621-1 5.4 6622-1/6622-2, Internal bevel, IF/IFU 6624-1/6624-3 Internal notch 6621-4 Internal step, IW/IWU 6622-1, 6624-1 Joint configuration 6621-4 8.1 6621-2/ Keystone angle 6624-1/6624-2, 6624-3/6624-4 Keystone rings 6624-1/6624-3 Land offset Land spacing Land width Light tightness B3 h4, h5 6621-2/ 4.2/ 6626/6626-2/6626-3 4.4/Figures to 6621-1 5.7 6626/6626-2/6626-3 6621-1/6625 5.5/6 6626/6626-2/6626-3 7/8/5.2 6621-2 4.2/ 6621-4 7.2 `,,```,,,,````-`-`,,`,,`,`,,` - 24 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) Characteristic/Term Symbol ISO Reference Clause/Subclause Macro-cracks (chromium) 6621-5 4.5 Macro cracks (nitrided surface) 6621-5 4.5 Marking 6621-4 Material removal 6621-5 4.4-Table 6621-3 Materials Measuring principles (inspection) 6626/6626-2/6626-3 5.4/6.4/6.4 6627 6621-2 Modulus of elasticity, E Napier rings (see scraper rings) 6621-3 6621-4 7.4 6623 Negative twist Nitrided surfaces 6621-1 4.3 6622-1/6622-2 5.6 / 5.7 6621-4 10.3 6622-2, 6624-3, 6624-4 6621-2/6621-4/6622-2, 4.2/10.3/5.9 6624-3, 6624-4 5.4/5.4 6626-3/6627 5.6/5.2 6621-1 6621-1 5.2/5.3/6.2 Notch against ring rotation 6621-4 8.1/8.2 Obliqueness 6621-2 4.2 6621-1 5.7 Nitrided case depth Nomenclature piston rings d1 Oil control rings 6625 to 6627 6621-1/6622-1 5.5/5.8 6624-2 5.2 6622-2 5.7 6624-3/6624-4 5.1/5.2 6621-2 4.2 6621-4 7.1 6621-4 11.3 6621-1 5.4,5.5 6621-4 10 6621-1/6621-4 5.4/Table 16, 20 22 6621-5 4.4 Peripheral surface 6621-1 5.4 Peripheral surface coatings 6621-4 10 Outside chamfered edges, KA Outside rounded edges Ovality, (see ring shape) U Packing Peripheral edges Peripheral edges at gap 25 © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS `,,```,,,,````-`-`,,`,,`,`,,` - Nominal diameter Not for Resale ISO 6621-1:2007(E) `,,```,,,,````-`-`,,`,,`,`,,` - Characteristic/Term Symbol Peripheral surface configurations ISO Reference Clause/Subclause 6621-1 4.2 6621-4 6621-5 Peripheral surface profile (deviations) 6621-5 7.2 Phosphate treatment 6621-4 10.4 6621-1 6.2 6621-2 4.2 Piston ring classifications 6621-1 Piston ring codes and descriptions 6621-4 4-Table Piston ring types 6621-1 Plain 6621-1 4.4 Point deflection 6621-2 4.2 Pores/porosities 6621-5 4.2/Table 1/4.5 6621-1 4.3 6622-1/6622-2 5.5 6624-1/6624-3 5.2 Pressure pattern 6621-1 6.2 Quality requirements (visual features) 6621-5 4.1 6621-1 5.7 6621-1/6621-2 5.1/5.3 Peripheral surface machining Pin point or burry light Positive twist Radial thickness with coil spring a12 Radial wall thickness a1 6622 ff Rail (see segment) 6621-1/6627 5.7/5.2 Raised material (marking) 6621-5 6621-1 6.1 Rectangular rings 6622-1/6622-2 Reduced m/d1 ratio 6621-4 7.4 Reference plane (see Datum surface) 6621-1 6.4 Ring back (back of the ring) 6621-1 5.1 6621-1/6621-4 5.2/7.3 Ring gauge 6621-1 6.4 Ring groove (piston) 6621-1 6.3 Ring rotation (prevent of) 6621-4 6621-2 4.2 6621-4 7.1 6621-1/6621-2 5/4.2.1 Ring gap (closed gap) s1 Ring shape (see ovality) Ring width h1 6622-1 ff Roughness (see surface roughness) 6621-2/6621-4 4.2/9 Sand inclusions 6621-5 4.2-Table 26 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) Characteristic/Term Symbol ISO Reference Clause/Subclause Scraper rings (Napier rings) 6623 Scratches 6621-5 4.3 Seating tab angle θ 6627 5.7 Seating tab height a14 6627 5.7 6621-1/6627 5.7/5.2 6627 5.2 Side faces 6621-1/6621-4 5/9.2 Side machining 6621-4 Side notch 6621-4 8.2 6625 4.1 6626/6626-2/6626-3 4.1/5.1/5.5 6621-1 5.7 6625 4.1 6626/6626-2/6626-3 4.2/5.2 6621-1/6626-3 5.7/5.5 6621-1 5.7 6625 6626/6626-2/6626-3 7/8/5.5 Segment Segment width h12 Slot arrangement Slot length w1 Slot spacing w3 Slot width c1 6621-1 Slotted oil-control rings 6625/6626/6626-2 Spacer radial thickness a8 6627 4.2 Spacer width h13 6627 4.2 6621-4/6622-1/6622-2 10.2/5.11/5.8 6624-1/6624-2/ 6624-3/6624-4 5.4/5.3/5.4/5.3 Spray coatings (defects) 6621-5 4.4/4.5 Spray coating hardness 6621-4 10.2 Spring excursion 6626/6626-2/6626-3 5.2/6.2/6.2 Spray coating Steel segments (see segment) Step depth a2 6623 Table 8/Table Step width h2 6623 Table 8/Table Strength properties (mechanical properties) 6621-3 Surface machining, coating 6621-4 Surface roughness 6621-2/6621-4 4.2/9 Surface treatment 6621-4 10.4 6621-2 Tangential force Ft 6621-4 6622-1 ff Tangential force loss (heat set) 6621-5 `,,```,,,,````-`-`,,`,,`,`,,` - 7.4/7.5/7.6 5.2 27 © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS 4.2 Not for Resale ISO 6621-1:2007(E) Characteristic/Term Symbol ISO Reference Clause/Subclause Taper-faced rings 6621-1 ff until 6624-4 Tapered peripheral surface 6621-1 ff until 6624-4 Temperature influence (heat set) 6621-5 5.2 6621-2 4.2 6622-1/6622-2 5.7/5.5-5.6 6624-1/6624-3 5/5 6621-1 5.1 6621-2 4.2.3 6621-1 5.6 V-groove (oil-control-ring) 6626-3 3.4 Visual defects (features) 6621-5 6621-1/6621-2 5.3/4.2.2 Torsion/twist Total free gap (see free gap) m Undercut radius r2 Wall thickness (see radial wall thickness) Witness line a1 6622-1 ff 6621-1 6.2.2 `,,```,,,,````-`-`,,`,,`,`,,` - 28 Organization for Standardization Copyright International Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2007 – All rights reserved Not for Resale ISO 6621-1:2007(E) Bibliography `,,```,,,,````-`-`,,`,,`,`,,` - [1] ISO 6622-1, Internal combustion engines — Piston rings — Part 1: Rectangular rings made of cast iron [2] ISO 6622-2, Internal combustion engines — Piston rings — Part 2: Rectangular rings made of steel [3] ISO 6623, Internal combustion engines — Piston rings — Scraper rings made of cast iron [4] ISO 6624-1, Internal combustion engines — Piston rings — Part 1: Keystone rings made of cast iron [5] ISO 6624-2, Internal combustion engines — Piston rings — Part 2: Half keystone rings made of cast iron [6] ISO 6624-3, Internal combustion engines — Piston rings — Part 3: Keystone rings made of steel [7] ISO 6624-4, Internal combustion engines — Piston rings — Part 4: Half keystone rings made of steel [8] ISO 6625, Internal combustion engines — Piston rings — Oil control rings [9] ISO 6626, Internal combustion engines — Piston rings — Coil-spring-loaded oil control rings [10] ISO 6626-2, Internal combustion engines — Piston rings — Part 2: Coil-spring-loaded oil control rings of narrow width made of cast iron [11] ISO 6626-3, Internal combustion engines — Piston rings — Part 3: Coil-spring-loaded and nitrided oil control rings made of steel [12] ISO 6627, Internal combustion engines — Piston rings — Expander/segment oil-control rings 29 © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO 6621-1:2007(E) `,,```,,,,````-`-`,,`,,`,`,,` - ICS 01.040.43; 43.060.10 Price based on 29 pages © ISO 2007 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale