# SIST EN 20286-1:2000

(Main)## ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits (ISO 286-1:1988)

## ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits (ISO 286-1:1988)

## ISO-System für Grenzabmaße und Passungen - Teil 1: Grundlagen für Toleranzen, Abmaße und Passungen (ISO 286-1:1988)

## Systeme ISO de tolérances et d'ajustements - Partie 1: Base de tolérances, écarts et ajustements (ISO 286-1:1988)

## ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits (ISO 286-1:1988)

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### Standards Content (sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits (ISO 286-1:1988)ISO-System für Grenzabmaße und Passungen - Teil 1: Grundlagen für Toleranzen, Abmaße und Passungen (ISO 286-1:1988)Systeme ISO de tolérances et d'ajustements - Partie 1: Base de tolérances, écarts et ajustements (ISO 286-1:1988)ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits (ISO 286-1:1988)17.040.10Tolerance in ujemiLimits and fitsICS:Ta slovenski standard je istoveten z:EN 20286-1:1993SIST EN 20286-1:2000en01-december-2000SIST EN 20286-1:2000SLOVENSKI

STANDARDSIST EN 20286-1:2000

SIST EN 20286-1:2000

SIST EN 20286-1:2000

SIST EN 20286-1:2000

INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXJJYHAPOAHAR OPTAHM3A~Mfl f-t0 CTAHflAPTM3A~MM IS0 system of limits and fits - Part I : Bases of tolerances, deviations and fits Syst&me IS0 de tokkances et d’ajustements - Partie 7 : Base des tokances, harts et ajustements IS0 286-l First edition 1988-09-15 Reference number IS0 286-l : 1988 (E) SIST EN 20286-1:2000

Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (is0 member bodies). The work of preparing International Standards is normally carried out through IS0 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. This part of IS0 286 has been prepared by ISO/TC 3, Limits and fits, and, together with IS0 286-2, completes the revision of ISO/R 286, /SO system of limits and fits. ISO/R 286 was first published in 1962 and subsequently confirmed in November 1964; it was based on ISA Bulletin 25 first published in 1940. The major changes incorporated in this part of IS0 286 are as follows: a) The presentation of the information has been modified so that IS0 286 can be used directly in both the design office and the workshop. This has been achieved by separating the material dealing with the bases of the system, and the calculated values of standard tolerances and fundamental deviations, from the tables giving specific limits of the most commonly used tolerances and deviations. b) The new symbols js and JS replace the former symbols js and Js (i.e. s and S are no longer placed as subscripts) to facilitate the use of the symbols on equipment with limited character sets, e.g. computer graphics. The letters “s” and “S” stand for “symmetrical deviation”. c) Standard tolerances and fundamental deviations have been included for basic sizes from 500 to 3 150 mm as standard requirements (these were previously included on an experimental basis only). d) Two additional standard tolerance grades, IT17 and IT18, have been included. e) Standard tolerance grades IT01 and IT0 have been deleted from the main body of this part of IS0 286, although information on these grades is given in annex A for users who may have a requirement for such grades. f) Inch values have been deleted. 9) The principles, terminology bY contemporary technology. and symbols aligned required Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. 0 International Organization for Standardization, 1988 0 Printed in Switzerland ii SIST EN 20286-1:2000

ISO286-1:1988 EI Contents 6 7 8 9 IO Introduction. ....................................................... 1 Scope ............................................................. 1 Field of application .................................................. 1 References ......................................................... 1 Terms and definitions ................................................ 2 Symbols, designation and interpretation of tolerances, deviations andfits.. .......................................................... 6 Graphical representation ............................................. 9 Reference temperature ............................................... 10 Standard tolerances for basic sizes up to 3 150 mm. ...................... 10 Fundamental deviations for basic sizes up to 3 150 mm ................... 10 Bibliography ........................................................ 16 Annexes A Bases of the IS0 system of limits and fits ............................... 17 B Examples of the use of IS0 286-l ....................................... 23 C Equivalentterms .................................................... 24 . . . III SIST EN 20286-1:2000

This page intentionally left blank SIST EN 20286-1:2000INTERNATIONAL STANDARD IS02864 : 1988 (E) IS0 system of limits and fits - Part 1: Bases of tolerances, deviations and fits 0 Introduction The need for limits and fits for machined workpieces was brought about mainly by the inherent inaccuracy of manufac- turing methods, coupled with the fact that “exactness” of size was found to be unnecessary for most workpieces. In order that function could be satisfied, it was found sufficient to manufacture a given workpiece so that its size lay within two permissible limits, i.e. a tolerance, this being the variation in size acceptable in manufacture. Similarly, where a specific fit condition is required between mating workpieces, it is necessary to ascribe an allowance, either positive or negative, to the basic size to achieve the re- quired clearance or interference, i.e. a “deviation”. With developments in industry and international trade, it became necessary to develop formal systems of limits and fits, firstly at the industrial level, then at the national level and later at the international level. This International Standard therefore gives the internationally accepted system of limits and fits. Annexes A and B give the basic formulae and rules necessary for establishing the system, and examples in the use of the standard are to be regarded as an integral part of the standard. Annex C gives a list of equivalent terms used in IS0 286 and other International Standards on tolerances. 1 Scope This part of IS0 286 gives the bases of the IS0 system of limits and fits together with the calculated values of the standard tolerances and fundamental deviations. These values shall be taken as authoritative for the application of the system (see also clause A. 1). This part of IS0 286 also gives terms and definitions together with associated symbols. 2 Field of application The IS0 system of limits and fits provides a system of tolerances and deviations suitable for plain workpieces.’ For simplicity and also because of the importance of cylindrical workpieces of circular section, only these are referred to ex- plicitly. It should be clearly understood, however, that the tolerances and deviations given in this International Standard equally apply to workpieces of other than circular section. In particular, the general term “hole” or “shaft” can be taken as referring to the space contained by (or containing) the two parallel faces (or tangent planes) of any workpiece, such as the width of a slot or the thickness of a -key. The system also provides for fits between mating cylindrical features or fits between workpieces having features with parallel faces, such as the fit between a key and keyway, etc. NOTE - It should be noted that the system is not intended to provide fits for workpieces with features having other than simple geometric forms. For the purposes of this part of IS0 286, a simple geometric form consists of a cylindrical surface area or two parallel planes. 3 References NOTE - See also clause 10. IS0 1, Standard reference temperature for industrial length measurements. IS0 286-2, IS0 system of limits and fits - Part 2: Tables of standard tolerance grades and limit deviations for holes and shafts. IS01 R 1938, IS0 system of limits and fits - Inspection of plain workpieces. 1 ) IS0 8015, Technical drawings - Fundamental tolerancing principle. 1) At present under revision. 1 SIST EN 20286-1:2000

Is0 286-1 : 1988 E) 4 Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. It should be noted, however, that some of the terms are defined in a more restricted sense than in common usage. 4.1 shaft: A term used, according to convention, to describe an external feature of a workpiece, including features which are not cylindrical (see also clause 2). 4.1.1 basic shaft: Shaft chosen as a basis for a shaft-basis system of fits (see also 4.11.1). For the purposes of the IS0 system of limits and fits, a shaft the upper deviation of which is zero. 4.2 hole : A term used, according to convention, to describe an internal feature of a workpiece, including features which are not cylindrical (see also clause 2). 4.2.1 basic hole: Hole chosen as a basis for a hole-basis system of fits (see also 4.11.2). For the purposes of the IS0 system lower deviation of which is zero. of limits and fits, a hole the 4.5 zero line: In a graphical representation of limits and fits, the straight line, representing the basic size, to which the devi- ations and tolerances are referred (see figure 7). According to conventio n, the zero line is with positive deviations shown above and below (see figure 2). Zero line (4.5) ti zf : w .- cn 0 .a 8 M 4.3 size : A number expressing, in numerical value of a linear dimension. a particular unit, the Figure 1 - Basic 4.3.1 basic size; nominal size: The size from which the limits of size are derived by the application of the upper and lower deviations (see figure 1). NOTE - e.g. 32; The basic size 15; 8,75; 0,5; can be a etc. or a number, 4.3.2 actual size: The size of a feature, obtained by measurement. 4.3.2.1 actual local size: Any individual distance at any cross-section of a feature, i.e. any size measured between any two opposite points. 4.3.3 limits of size: The two extreme permissible sizes of a feature, between which the actual size should lie, the limits of size being included. 4.3.3.1 maximum limit of size: The greatest permissible size of a feature (see figure 1). 4.3.3.2 minimum limit of size : The smallest permissible size of a feature (see figure 1). 4.4 limit deviations. system: A system of standardized tolerances and Es drawn horizontally, negative deviations size, and maxim limits of size urn and minimum 4.6 deviation: The algebraic difference between a size (actual size, limit of size, etc.) and the corresponding basic size. NOTE - Symbols for shaft deviations are lower case letters (es, ei) and symbols for hole deviations are upper case letters (Es, EI) (see figure 2). 4.6.1 limit deviations : Upper deviation and lower deviation. 4.6.1.1 upper deviation (ES, es) : The algebraic difference between the maximum limit of size and the corresponding basic size (see figure 2). 4.6.1.2 lower deviation (EL ei) : The algebraic difference between the minimum limit of size and the corresponding basic size (see figure 2). 4.6.2 fundamental deviation: For the purposes of the IS0 system of limits and fits, that deviation which defines the position of the tolerance zone in relation to the zero line (see figure 2). NOTE - This may be either the upper or lower deviation, but, accord- ing to convention, the fundamental deviation is the one nearest the zero line. 4.7 size tolerance: The difference between the maximum limit of size and the minimum limit of size, i.e. the difference between the upper deviation and the lower deviation. NOTE - The tolerance is an absolute value without sign. 2 SIST EN 20286-1:2000

IS0 286-l I 1988 E) + 5 P 0 l - z 0 I .- 2 n - - Lower deviation (EI, ei 1 (4.6.1.2) Tolerance zone (4.7.3) tolerance (4.7) Zero line (4.5) A T - (ES, es) (4.6.1.1) ,~ w - F- ti s 8 .- cn 0 .- Ei m Figure 2 - Conventional representation of a tolerance zone 4.7.1 standard tolerance (IT) : For the purposes of the IS0 system of limits and fits, any tolerance belonging to this system. NOTE - The letters of the symbol IT stand for “International Tolerance” grade. 4.7.2 standard tolerance grades: For the purposes of the IS0 system of limits and fits, a group of tolerances (e.g. IJ7), considered as corresponding to the same level of accuracy for all basic sizes. 4.7.3 tolerance zone : In a graphical representation of tolerances, the zone, contained between two lines representing the maximum and minimum limits of size, defined by the magnitude of the tolerance and its position relative to the zero line (see figure 2). 4.7.4 tolerance class: The term used for a combination of fundamental deviation and a tolerance grade, e.g. h9, D13, etc. 4.7.5 standard tolerance factor (i, I): For the purposes of the IS0 system of limits and fits, a factor which is a function of the basic size, and which is used as a basis for the determi- nation of the standard tolerances of the system. NOTES 1 The standard tolerance factor i is applied to basic sizes less than or equal to 500 mm. 2 The standard tolerance factor I is applied to basic sizes greater than 500 mm. 4.8 clearance: The positive difference between the sizes of the hole and the shaft, before assembly, when the diameter of the shaft is smaller than the diameter of the hole (see figure 3). r Clearance (4.8) Figure 3 - Clearance 4.8.1 minimum clearance: In a clearance fit, the positive difference between the minimum limit of size of the hole and the maximum limit of size of the shaft (see figure 4). 4.8.2 maximum clearance: In a clearance or transition fit, the positive difference between the maximum limit of size of the hole and the minimum limit of size of the shaft (see figures 4 and 5). 4.9 interference : The negative difference between the sizes of the hole and the shaft, before assembly, when the diameter of the shaft is larger than the diameter of the hole (see figure 6). 4.9.1 minimum interference: In an interference fit, the negative difference, before assembly, between the maximum limit of size of the hole and the minimum limit of size of the shaft (see figure 7). . A- C- 4 s ti ii 5 a z E i .- .- ; 1 I ci 06 5 Figure 4 - Clearance fit 3 SIST EN 20286-1:2000

IS0 286-1 : 1988 (E) Maximum r clearance (4.8.2) 1 Maximum Maximum Minimum interference ‘-1 I- interference interference 2 (4.9.2) Figure 5 - Transition fit Interference Figure 6 - Interference Figure 7 - Interference fit (4.9) 4.9.2 maximum interference: In an interference or tran- sition fit, the negative difference, before assembly, between the minimum limit of size of the hole and the maximum limit of size of the shaft (see figures 5 and 7). 4.10 fit: The relationship resulting from the difference, before assembly, between the sizes of the two features (the hole and the shaft) which are to be assembled. 4.10.1 clearance fit: A fit that always provides a clearance between the hole and shaft when assembled, i.e. the minimum size of the hole is either greater than or, in the extreme case, equal to the maximum size of the shaft (see figure 8). Hole Hole Shaft Shaft Figure 8 - Schematic representation of clearance fits 4.10.2 interference fit: A fit which everywhere provides an interference between the hole and shaft when assembled, i.e. the maximum size of the hole is either smaller than or, in the ex- treme case, equal to the minimum size of the shaft (see figure 9). Shaft Hole Shaft t Hole Zero line . NOTE - The two mating parts of a fit have a common basic size. Figure 9 - Schematic representation of interference fits 4 SIST EN 20286-1:2000

IS0 286-l : 1988 (El 4.103 transition fit: A fit which may provide either a clearance or an interference between the hole and shaft when assembled, depending on the actual sizes of the hole and shaft, i.e. the tolerance zones of the hole and the shaft overlap com- pletely or in part (see figure IO). . . . Shaft Hole Zero line , Figure 10 - Schematic representation of transition fits 4.10.4 variation of a fit: The arithmetic sum of the tolerances of the two features comprising the fit. NOTE - The variation of a fit is an absolute value without sign. 4.11 fit system : A system of fits comprising shafts and holes belonging to a limit system. 4.11.1 shaft-basis system of fits: A system of fits in which the required clearances or interferences are obtained by associating holes of various tolerance classes with shafts of a single tolerance class. For the purposes of the IS0 system of limits and fits, a system of fits in which the maximum limit of size of the shaft is identical to the basic size, i.e. the upper deviation is zero (see figure I I). Shaft “h” L Basic size (4.3.1) NOTES 1 The horizontal continuous lines represent the fundamental devi- ations for holes or shafts. 2 The dashed lines represent the other limits and show the possibility of different combinations between holes and shafts, related to their grade of tolerance (e.g. G71h4, H6/h4, M5/h4). 4.11.2 hole-basis. system of fits : A system of fits in which the required clearances or interferences are. obtained by associating shafts of various tolerance classes with holes of a single tolerance class. For the purposes of the IS0 system of limits and fits, a system of fits in which the minimum limit of size of the hole is identical to the basic size, i.e. the lower deviation is zero (see figure 12). - Basic size (4.3.1) NOTES 1 The horizontal continuous lines represent the fundamental devi- ations for holes or shafts. 2 The dashed lines represent the other limits and show the possibility of different combinations between holes and shafts, related to their grade of tolerance (e.g. H6/ h6, H6/js5, H6/p4). Figure 12 - Hole-basis system of fits 4.12 maximum material limit (MML): The designation applied to that of the two limits of size which corresponds to the maximum material size for the feature, i.e. - the maximum (upper) limit of size for an external feature (shaft), - the minimum (lower) limit of size for an internal feature (hole). NOTE - Previously called “GO limit”. 4.13 least material limit (LMLI : The designation applied to that of the two limits of size which corresponds to the minimum material size for the feature, i.e. - the minimum (lower) limit of size for an external feature (shaft), - the maximum (upper) limit of size for an internal feature (hole). Figure 11 - Shaft-basis system of fits NOTE - Previously called “NOT GO limit”. 5 SIST EN 20286-1:2000

IS0 286-1 : 1988 (E) Examples : 5 Symbols, designation and interpretation of tolerances, deviations and fits 5.1 Symbols 5.1 .l Standard tolerance grades The standard tolerance grades are designated by the letters IT followed by a number, e.g. IJ7. When the tolerance grade is associated with (a) letter(s) representing a fundamental deviation to form a tolerance class, the letters IT are omitted, e.g. h7. NOTE - The IS0 system provides for a total of 20 standard tolerance grades of which grades IT1 to IT18 are in general use and are given in the main body of the standard. Grades IT0 and ITOl, which are not in general use, are given in annex A for information purposes. 32H7 8OjsI5 10096 -0 012 IO0 -0:034 ATTENTION - In order to distinguish between holes and shafts when transmitting information on equipment with limited character sets, such as telex, the designation shall be prefixed by the following letters: - H or h for holes; - S or s for shafts. Examples : 5OH5 becomes H5OH5 or h5Oh5 5Oh6 becomes S5OH6 or s5Oh6 5.1.2 Deviations 5.1.2.1 Position of tolerance zone This method drawings. of designation shall not be on The position of the tolerance zone with respect to the zero line, which is a function of the basic size, is designated by (an) upper case letter(s) for holes (A . . . ZC) or (a) lower case letter(s) for shafts (a . . . zc) (see figures I3 and 14). 5.2.3 Fit A fit requirement between mating features shall be designated bY NOTE - To avoid confusion, the following letters are not used : a) the common basic size; I, i; L, I; 0, 0; Q, q; W, w. b) the tolerance class symbol for the hole; 5.1.2.2 Upper deviations c) the tolerance class symbol for the shaft. Examples : The upper deviations are designated by the letters “ES” for holes and the letters “es” for shafts. Ii7 52H7lg6 or 52 - 96 5.1.2.3 Lower deviations The lower deviations are designated by the letters “El” for holes and the letters “ei” for shafts. ATTENTION - In order to distinguish between the hole and the shaft when transmitting information on equipment with limited character sets, such as telex, the designation shall be prefixed by the following letters: 5.2 Designation - H or h for holes; - S or s for shafts; 5.2.1 Tolerance class - and the basic size repeated. A tolerance class shall be designated by the letter(s) represent- ing the fundamental deviation followed by the number representing the standard tolerance grade. Examples : 52H7/g6 becomes H52H7/S52G6 or h52h7/s52g6 Examples : This method of designation shall not be used on drawings. H7 (holes) h7 (shafts) 5.3 Interpretation of a toleranced size 5.2.2 Toleranced size 5.3.1 Tolerance indication in accordance with IS0 8015 A toleranced size shall be designated by the basic size followed by the designation of the required tolerance class, or the ex- plicit deviations. The tolerances for workpieces manufactured to drawings marked with the notation, Tolerancing IS0 8015, shall be interpreted as indicated in 5.3. I. I and 5.3.1.2. SIST EN 20286-1:2000

Is0 286-I : 1988 (El 2 0 .- z .- $ u 5 E E 3 z NOTES a) Holes (internal features) b) Shafts (external features) I According to convention, the fundamental deviation is the one defining the nearest limit to the zero line. 2 For details concerning fundamental deviations for J/j, K/k, M/m and N/n, see figure 14. Figure 13 - Schematic representation of the positions of fundamental deviations SIST EN 20286-1:2000

60286-1:1988 E) I U N 0 CL P t 0 a 1 is . . CL) l- 0 z L t 0 I-- l- -- . . LLJ l- 0 z SIST EN 20286-1:2000

IS0 286-k 1988 a(E) 53.1 .I Linear size tolerances A linear size tolerance controls only the actual local sizes (two- point measurements) of a feature, but not its form deviations (for example circularity and straightness deviations of a cylin- drical feature or flatness deviations of parallel surfaces). There is no control of the geometrical interrelationship of individual features by the size tolerances. (For further information, see ISO/R 1938 and IS0 8015.) 5.3.1.2 Envelope requirement Single features, whether a cylinder, or established by two parallel planes, having the function of a fit between mating parts, are indicated on the drawing by the symbol @ in ad- dition to the dimension and tolerance. This indicates a mutual dependence of size and form which requires that the envelope of perfect form for the feature at maximum material size shall not be violated. (For further information, see ISO/R 1938 and IS0 8015.) NOTE - Some national standards (which should be referred to on the drawing) specify that the envelope requirement for single features is the norm and therefore this is not indicated separately on the drawing. 53.2 Tolerance indication not in accordance with IS0 6015 The tolerances for workpieces manufactured to drawings which do not have the notation, Tolerancing IS0 6015, shall be interpreted in the following ways within the stipulated length : a) For holes The diameter of the largest perfect imaginary cylinder, which can be inscribed within the hole so that it just con- tacts the highest points of the surface, should not be smaller than the maximum material limit of size. The maximum diameter at any position in the hole shall not exceed the least material limit of size. b) For shafts The diameter of the smallest perfect imaginary cylinder, which can be circumscribed about the shaft so that it just contacts the highest points of the surface, should not be larger than the maximum material limit of size. The mini- mum diameter at any position on the shaft shall be not less than the least material limit of size. The interpretations given in a) and b) mean that if a workpiece is everywhere at its maximum material limit, that workpiece should be perfectly round and straight, i.e. a perfect cylinder. Unless otherwise specified, and subject to the above require- ments, departures from a perfect cylinder may reach the full value of the diameter tolerance specified. For further informa- tion, see ISO/R 1938. NOTE - In special cases, the maximum form deviations permitted by the interpretations given in a) and b) may be too large to allow satisfac- tory functioning of the assembled parts: in such cases, separate tolerances should be given for the form, e.g. separate tolerances on circularity and/or straightness (see IS0 1101). 6 Graphical representation The major terms and definitions given in clause 4 are illustrated in figure 15. In practice, a schematic diagram such as that shown in figure 16 is used for simplicity. In this diagram, the axis of the workpiece, which is not shown in the figure, according to con- vention always lies below the diagram. In the example illustrated, the two deviations positive and those of the shaft are negative. of the hole are K zi 8 r Upper deviation (4.6.1.1) - r Lower deviation (4.6.1.2) Hole (4.2) 1 Minimum limit of size (4.3.3.2) - Maximum limit of size (4.3.3.1) Basic size (4.3.1) A Figure 15 - Graphical representation + 5 ii 0 .- % O- .- 2 n - Hole Shaft Figure 16 - Simplified schematic diagram SIST EN 20286-1:2000

IS0 286-l : 1988 (El 7 Reference temperature The temperature at which the dimensions of the IS0 system of limits and fits are specified is 20 OC (see IS0 I). 8 Standard tolerances for basic sizes up to 315Omm 8.1 Basis of the system The bases for calculating the standard tolerances are given in annex A. 8.2 Values of standard tolerance grades (IT) Values of standard tolerance grades IT1 to IT18 inclusive are given in table 1. These values are to be taken as authoritative for the application of the system. NOTE - Values for standard tolerance grades IT0 and IT01 are given in annex A. 9 Fundamental deviations for basic sizes up to315Omm 9.1 Fundamental deviations for shafts [except deviation js (see 9.3)] The fundamental deviations for shafts and their respective sign ( + or - 1 are shown in figure 17. Values for the fundamental deviations are given in table 2. The upper deviation (es) and lower deviation (ei) are estab- lished from the fundamental deviation and the standard tolerance grade (IT) as shown in figure 17. Deviations a to h Zero line es = negative ( - 1 funda- mental deviation ei = es - IT Deviations k to zc ei = positive ( + ) funda- mental deviation es = ei + IT Figure 17 - Deviations for shafts 9.2 Fundamental deviations for holes [except deviation JS (see 9.311 The fundamental deviations for holes and their respective sign ( + or - ) are shown in figure 18. Values for the fundamental deviations are given in table 3. The upper deviation (ES) and lower deviation (H) are established from the fundamental deviation and the standard tolerance grade (IT) as shown in figure 18. Deviations A to H EI = positive (+ 1 funda- mental deviation ES = EI + IT Deviations K to ZC (not valid for tolerance grades less than or equal to IT8 of deviation K and tolerance class M8) Zero line ES = negative ( - 1 funda- mental deviation EI = ES - IT Figure 18 - Deviations for holes 9.3 Fundamental deviations js and JS (see figure 19) The information given in 9.1 and 9.2 does not apply to fun- damental deviations js and JS, which are a symmetrical distribution of the standard tolerance grade about the zero line, i.e. for js: IT es = ei = - 2 and for JS: IT ES = EI.= - 2 es IT r2 r ES h w El . Shaft I Hole L IT 2 Figure 19 - Deviations js and JS SIST EN 20286-1:2000

IS0 286-1 : 1988 (EI 9.4 Fundamental deviations j and J The information given in 9.1 to 9.3 does not apply to fundamental deviations j and J, which are, for the most part, asymmetrical distributions of the standard tolerance grade about the zero line (see IS0 286-2, tables 8 and 24). Table 1 - Numerical values of standard tolerance grades IT for basic sizes up to 3 150 mm ‘) Basic size Standard tolerance grades mm IT7 IT8 1 IT8 1 IT10 ] IT11 1 IT12 1 IT13 1 lTl43)1 IT153) 1 IT1631 ITl73)I IT1831 I up to Tolerances Above and in- cluding IJm mm - 33) 0,8 I,2 2 3 4 6 10 14 25 40 60 0,l 0,14 0,25 0,4 0,6 1 114 3 6 1 1,5 2,5 4 5 8 12 18 30 48 75 0,12 0,18 0,3 0,48 0,75 1,2 I,8 6 10 1 I,5 2,5 4 6 9 15 22 36 58 90 0,15 0,22 0,36 0,58 0;9 I,5 2,2 10 18 I,2 2 3 5 8 11 18 27 43 70 110 0,18 0,27 0,43 0,7 1,1' I,8 2,7 18 30 I,5 2,5 4 6 9 13 21 33 52 84 130 0,21 0,33 0,52 0,84 I,3 2,l 3,3 30 50 I,5 2,5 4 7 11 16 25 39 62 100 160 0,25 0,39 0,62 1 1,6 2,5 3,9 50 80 2,, 3 5 8 13 19 30 46 74 120 190 0,3 0,46 0,74 1,2 I,9 3 4,6 80 120 2,5 4 6 10 15 22 35 54 87 140 220 0,35 0,54 0,87 I,4 2,2 3,5 5,4- 120 180 3,5 5 8 12 18 25 40 63 100 160 250 0,4 0,63 1 I,6 2,5 4 613 180 250 4,5 7 10 14 20 29 46 72 115 185 290 0,46 0,72 I,15 1,85 2,9 4,6 7,2 250 315 6 8 12 16 23 32 52 81 130 210 320 0,52 0,81 I,3 2,l 3,2 5,2 8,l 315 400 7 9 13 18 25 36 57 89 140 230 360 0,57 0,89 I,4 2,3 3,6 5,7 8,9 d-00 500 8 10 15 20 27 40 63 97 155 250 400 0,63 0,97 1,55 2,5 4 6,3 9,7 ; 500 6302) 9 11 16 22 32 44 70 110 175' 280 440 0,7 I,1 I,75 2,8 4,4 7 11 630 8002) 10 13 18 25 36 50 80 125 200 320 500 0,8 I,25 2 3,2 5 8 12,5 800 10002) 11 15 21

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