Disclosure to Promote the Right To Information

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1 इ टरन ट म नक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. ज न1 क अ+धक र, ज 1 क अ+धक र Mazdoor Kisan Shakti Sangathan The Right to Information, The Right to Live प0र 1 क छ ड न' 5 तरफ Jawaharlal Nehru Step Out From the Old to the New IS 7615 (2003): System of Cone Tolerances for Conical Workpieces from C=1:3 to 1:500 and Lengths from 6 to 630 mm [PGD 20: Engineering Standards]! न $ एक न' भ रत क +नम-ण Satyanarayan Gangaram Pitroda Invent a New India Using Knowledge! न एक ऐस खज न > ज कभ च0र य नहB ज सकत ह ह Bhartṛhari Nītiśatakam Knowledge is such a treasure which cannot be stolen

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4 Indian Standard SYSTEM OF CONE TOLERANCE FOR CONICAL WORKPIECE FROM C = 1:3 TO 1:500 AND LENGTHS FROM 6 TO 630 mm (Second Revision) lcs BIS 2003 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI December 2003 Price Group 7

5 Engineering Standards Sectional Committee, BP 20 FOREWORD This Indian Standard (Second Revision) was adopted by the Bureau of Indian Standards, after the draft finalized by the Engineering Standards Sectional Committee had been approved by the Basic and Production Engineering Division Council. This standard was first published in 1975 and subsequently revised in IS 7615 : 1993 System of cone tolerance for conical work piece from C = 1:3 to 1:500 and lengths from 6 to 630 mm was identical with 1S0 1947: 1973 published under dual numbering system. The 1S0 Technical Committee (ISO/TC 213) had withdrawn 1S : The Committee, deliberated on the matter and felt that an Indian Standard on this subject is required to Indian industry. However after withdrawal of ISO 1947: 1973 the dual number status of 1S7615 :1993 cannot be continued, therefore, the Committee decided to retain IS7615 and develop an indigenous standard on the subject as its second revision.

6 Indian Standard SYSTEM OF CONE TOLERANCE FOR CONICAL WORKPIECE FROM C = 1:3 TO 1:500 AND LENGTHS FROM 6 TO 630 mm (Second Revision) 1 SCOPE 1.1 This standard covers the cone tolerance system which applies to rigid conical work piece from C = 1:3 to 1:500 and lengths from 6 to 630 mm. 1.2 The appropriate tolerances of this standard may also be used for prismatic work pieces, for example wedges, etc. 2 BASIS OF THE SYSTEM 2.1 Types of Cone Tolerance The following four types of tolerance provide the basis of the cone tolerance system: a) b) c) d) Cone diameter tolerance, T~ valid for all cone diameters within the cone length L; Cone angle tolerance, AT given in angular or linear dimensions (ATa or ATJ; Cone form tolerance, TF (tolerances for the straightness of the generator and for the circularity of the section); and Cone section diameter tolerance, T... given for the cone diameter in a defined sectio~. it is valid for the cone diameter of this section only. 2.2 Cone Diameter Tolerance, Cone Angle Tolerance and Cone Form Tolerance Normal cases shall be handled by application of the cone diameter tolerance, To only. It includes the two tolerances of the types 2.1 (b) and (c). This means that the deviations of these two types may, in principle, utilize the whole tolerance space given by the cone diameter tolerance, T~ In case of stronger requirements, the cone angle tolerance and the cone form tolerance may be reduced within the cone diameter tolerance, T~ by means of supplementary instructions. In this case, likewise, no point on the conical surface is permitted to lie outside the limit cones given by, T~ In practice, all types of tolerance generally exist at the same time and, as far as normal cases are concerned, each tolerance may occupy a part of the cone diameter tolerance, T~ only in such a way that no point on the conical surface lies outside the tolerance space. In other words, no point on the conical surface is permitted to lie outside the limit cones. 2.3 Cone Section Diameter Tolerance If for functional reasons, the cone diameter tolerance is required in a defined section, then the cone diameter tolerance, T~s (tolerance type d) shall be indicated. In this case, it is also necessary to indicate the cone angle tolerance If general tolerances for the cone angle are specified, for example in an any document, and if it is referred to this tolerance, then it is not necessary to indicate special cone angle tolerances. 3 DEFINITIONS 3.1 Definitions Relating to Cones Cone a) A conical surface or a conical workpiece (see Fig. 1) is defined by its geometrical dimensions. b) In the absence of any indication concerning the geometrical form, cone is understood to mean a straight circular cone or truncated cone. GENERATOR CONICAL SURFACE AND CONICAL WORKPIECE FIG. 1 CONE 1

7 3.1.2 Conical Surface A surface of revolution, which is formed by rotating a stnaight line (generator) around an axis with the straight line intersecting this axis at the apex (see Fig. 1). The parts of this infinite conical surface are also known as conical surface or cones. Similarly, cone is also the abbreviated designation of truncated cone Conical Workpiece A workpiece or portion of aworkpiece the main part of which is a conical surface (see Fig. 2 and Fig. 3) External Cone A cone, which limits the outside form of a conical feature of a workpiece (see Fig. 2 and Fig. 6) Internal Cone A cone, which limits the inside form ofa conical feature of workpiece (see Fig. 3 and Fig. 6) Basic Cone The geometrically ideal conical surface, which is given by its geometrically ideal conical surface, which is given by its geometrical dimensions. These are either: a) A basic cone diameter, the basic cone length and the basic rate of taper or the basic cone angle, or b) Two basic cone diameters and the basic cone length (see Fig. 4) Actual Cone That cone the conical surface of which has been found by measurement (see Fig. 5) Limit Cones a) b) The geometrically ideal coaxial surfaces, having the same basic cone angle, which result from the basic cone and the cone diameter tolerances. The difference between the largest and the smallest cone diameters is the same in all sections normal to the cone axis (see Fig. 8). The surface of the limit cones may be made to coincide by the axial displacement Generator The line of intersection of the conical surface with a section in the axial plane (see Fig. 1 and Fig. 6). 3.2 Definitions Relating to Size on Cones Cone Diameter The distance between two parallel Iines tangent to the intersection of the circular conical surface with aplane normal to the cone axis Basic cone diameters are as follows (see Fig. 4): a) Largest cone diameter, D; or b) c) Smallest cone diameter, d, or Cone diameter, d, at a place determined by its position in the axial direction Actual ConeDiameter, d. The distance between two parallel tangents to the intersection line of the surface of the actual cone with a defined plane normal to the cone axis (see Fig. 5) Limit Cone Diameters The diameters of the limit cones in each section in a plane normal to the axis (see Fig. 8) Basic Cone Length, L The distance in the axial direction between two limiting ends of a cone (see Fig. 4 and Fig. 6) Basic Cone Angle, a The angle formed by the two generators of the basic cone in a section in the axial plane (see Fig. 7) Limit Cone Angles The largest and the smallest cone angles resulting from the basic cone angle etand the dposition and magnitude of the cone angle tolerance (see Fig. 10) Cone Generating Angle, w2 The angle contained between a generator and the cone axis (see Fig. 7) Rate of Taper, C a) The ratio of the difference between the cone diameters D and d to the cone length L: c= = D-d L 2 tan+ b) The rate of taper is often indicated by the expressions 1:x or l/x and Cone 1:x for short. For example, C = 1:20 means that a diameter difference D dof 1mm occurs an axial distance L of 20 mm between the cone diameters D and d. 3.3 Definitions Relating to Cone Tolerances Cone Tolerance System A system containing the cone diameter tolerances, the cone angle tolerances and the tolerances on the cone form of the generator and the circumferential line of the section normal to the cone axis Cone Diameter Tolerance, T~ The difference between the largest and smallest permissible cone diameters in any section that is between the limit cones (see Fig. 8). 2

8 3.3.3 Cone Angle Tolerance A T ~ The difference between the largest and smallest permissible cone angles (see Fig. 10, Fig. 15 and Fig. 18) Cone Form Tolerances, T~ Tolerance on the straightness of the generator a) b) The distance between two parallel, straight lines between which the actual generator shall lie (see Fig. 8). The actual value for the error on straightness is taken as the distance between tw~ parallel straight lines touching the actual generator, and so placed that the distance be&veen them is a minimum Tolerance on the circularip of the section a) b) The distance between two coplanar concentric circles in a section normal to the axis between which the actual cone section shall be situated (see Fig. 9). The actual value for the error on circularity is taken as the distance between two coplanar concentric circles which touch the actual line of any section normal to the axis Cone Section Diameter Tolerance, T~~ The difference between the largest and smallest permissible cone diameters in a defined section (see Fig. 17). 3.4 Definitions Relating to Actual Cone Angles Actual Cone Angle a) In any axial plane section, the angle between the two pairs of parallel straight lines that enclose the form errors of the two generators in such a way that the maximum distance between them is the least possible value (see Fig. 11). b) For a given cone, there is not only one actual cone angle; for cones having deviations of circularity, the actual cone angle will be different in different axial planes (see et] and a2 in Fig. 11) Average Actual Cone Angle a) The arithmetical average value of the actual cone angle measured in accordance with in several equally distributed axial plane sections. b) Amongst the axial planes chosen, one at least shall cover the greatest deviation of circularity from the circle line of the cone diameter. 3.5 Definition Relating to Cone Tolerance Space Cone Tolerance Space a) For the conical surface, the space between the two limits cones. b) Cone tolerance space includes all the tolerances referred to in 3.3. It may be represented by tolerance zones in two plane sections (see Fig. 8, Fig. 9 and Fig. 13). 3.6 Definitions Relating to Cone Tolerance Zones Cone Diameter Tolerance Zone a) In a graphic representation, that zone, lying in the plane section of the cone axis, which is limited by the limit cones. b) The total tolerances zone is represented in Fig. 8 and Fig. 9 by the hatched portions which al~oindicate&e cone tolerance space. It includes the tolerances for the cone diameter, the cone angle, the roundness and the straightness which can occupy the whole cone tolerance zone. In general, each of these particular deviations occupies a part of the cone diameter tolerance zone only Tolerance Zone for the Cone Angle A fan-shaped zone within the limit cone angles. The inclination of the limit cones maybe indicated by plus, minus or plus/minus for the cone angle tolerances (see Fig. 12). For the indication of plus/minus, the values may be different Tolerance Zone for the Straightness of the Generator a) In a graphic representation, that zone (band) situated in any axial plane section and disposed on each side of the cone axis, which is determined by the form tolerance of the generators (see Fig. 8). b) As this zone is smaller than that referred to in 3.6.1, it only applies if the tolerance on the straightness of the generator is reduced with respect to the cone diameter tolerance zone. The actual generator has to be situated anywhere within a tolerance zone given by the tolerance for the straightness Tolerance zone for the roundness of the section: In a graphic representation, the zone lying in a section normal to the cone axis and formed by concentric circles (see Fig. 9). As this zone isnarrower than that referred to in it only applies if the tolerance for the roundness of the section is reduced with respect to the cone diameter )AT = Angle tolerance. 3

9 tolerance zone. The contour has to be situated anywhere within a tolerance zone given by the tolerance for the circularity of the section Cone Section Diameter Tolerance Zone The tolerance zone for the cone diameter in a defined section. It appears in that case if the cone diameter tolerance is indicated for fixed diameter only. 4 CONE DIAMETER TOLERANCE, TD 4.1 In general, the choice of the cone diameter tolerance, T~ is based on the large cone diameter, D. It is selected from the Indian Standard IT tolerances and applies over the whole of the cone length, L 4.2 If it is not required to indicate smaller tolerances of angle and form, a cone diameter tolerance, T~ given on the drawing, applies also to the angle and form deviations. It shall be borne in mind, however, that in this case all work pieces that conform to Fig. 14 and Fig. 15 shall be accepted. 4.3 The symbols of the ISO tolerances system shall be used to indicate the cone diameter tolerances referred to the corresponding cone diameter. If the conical surface of the conical work piece concerned is not intended for a cone fit, the tolerance positions JS and js shall be chosen for preference, for example, 40js CONE ANGLE TOLERANCE, AT 5.1 Cone Angle Tolerance Resulting from the Cone Diameter Tolerance, T~ The actual cone angle lies within the cone diameter tolerance zone in case of absence of any special indication of cone angle tolerances. The cone angles a.,,, and u~in(see Fig. 15) are thus the limit cone angles resulting from the cone diameter tolerance, T~. Consequently, in this case, the actual cone angle is permitted to be disposed with respect to the basic cone angle et from + A(x to Acx(for values of Aa, see Annex A). 5.2 Fixed Cone Angle Tolerance a) If the cone angle tolerance has to be smaller than that given by the cone diameter tolerance, it is necessary to establish the cone angle limits. For the cone angle tolerances, the deviations shall be indicated by plus, minus or plus/minus, for example, +A T, A T, + AT12. b) For the indication of plus/minus, the values may be different. 6 CONE FORM TOLERANCES, T~ Cone form tolerances comprise the tolerances on: a) the straightness of the generator (see Fig. 8). b) the circularity of the cone section (see Fig. 9). Cone form tolerances shall be especially indicated (in micrometers), if they shall be smaller than half of the cone diameter tolerance. 7 CONE SECTION DIAMETER TOLERNACE, T DS If the cone diameter tolerance should be reduced locally and shall be given for a defined section only, for functional of manufacturing reasons the cone diameter tolerance shall be indicated for this section only. 8 TABLE OF CONE ANGLE TOLERANCES 8.1 Structure of the Table (see Table 1) As the cone angle tolerances, A T have different functions they are stepped in grades represented numbers; for example AT 5. They are expressed in micro radians (p rad)]) for A T. or in micromet~es (pm) for A T~, calculated from the constant A T=value within a range of cone lengths. A ~~ is valid normal to the axiszl in the form of a diameter ddyerence. It must be smaller with respect to the cone diameter tolerance, T~ Taking account of the units (micrometres, microradians), the following relationship exists (see also Fig. 16): AT~=AT= x L The grade number for IT (diameter) and AT (angle) tolerances is chosen in such way that the same numbers correspond to approximately the same difllculties of manufacture. No direct relation isgiven, however, because the IT values are stepped in accordance with the diameter of cylindrical workpieces, whereas the AT values are stepped in accordance with the cone length, L The ratio for the cone angle tolerances for one ATgrade to the next higher grade is 1.6. It isnecessary to relate the cone angle tolerance, A Tto the cone length, L because the longer the length of cone, the better the angle may be met. The cone lengths L tlom 6 mm to 630 mm are divided into ten ranges with a stepped ratio of The AT. values decrease from one range of length to the next higher range by a step of 0.8, which corresponds to the experimental relationship. 1) 11 1 AT= - G 1 p rad = An angle producing an arc of length I ~m at a radial distanceof 1 m. 5 p rad = 1 (1 second):300 M rad = 1 (1 minute). The measurement normal to the cone axis is regarded as equivalent to the theoreticalcorrect measurementnormal to the generatoras the difference of the measuredatdvalues is only 2 percenteven for a cone 1:3. 4

10 As the A Twvalues are held constant in a cone length range, it is the corresponding A 1 ~values that vary. They are given for the limits of the ranges of lengths and increase from one length range to the next with a ratio of Figure 16shows the largest and smallest values for AT. resulting from the largest (L~u) and smallest (L~,,Jbasic lengths of a length range at a constant A T. value No relationship is provided for between the cone angle tolerance and the cone diameter because of lack of experience. The introduction of such a relationship shall be made in future if sufficient experience is available. In the case of conical workplaces with large cone diameter, it is left to the user to select a higher AT grade than that used for conical workplaces of small diameter If freer or coarser angle tolerances are necessary, they shall be calculated by division or multiplication by 1.6 from the AT 1 and AT 12 values respectively. The finer AT grades shall be designated AT O,AT 01. Table 1 Cone Angle Tolerances (Clause 8.1) [ Range of Cone Angle Toleranee Grades Cone AT 1 AT 2 AT 3 Length, L mm ATa A~, ATe A TD AT* A TD Over up to v rad seconds ~m L rad seconds ~m p rad seconds ~m (1) (2) (3) (4) (5) (6) (7) (8) (9) (lo) (11) lo ,, ,5,..0,8 50 I o , ,) , , o I * , ,/ ,, ,.,..3,2 12, , ,

11 1S 7615:2003 Table 1 (Continued) Range of Cone Length, f, Cone Angle Tolerance Grades AT 4 AT 5 mm AT. ATD AT= ATD ATm ATD Over up to p rad seconds pm v rad minutes gm A rad minutes ~m seconds seconds (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) S * lo I AT 6 Range of Cone Length, L Cone Angle Tolerance Grades AT 7 AT 8 AT 9 mm ATti ATD AT= ATD AT. ATD Over up to p rad minutes pm ISrad minutes pm /lrad minutes ~m seconds seconds seeonds (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) Io ? o S m m N I

12 Table 1 (Concluded) Rfirrge of Cnrse Cone Angle Tolerance Grades 1 Lmrgth, L mm A TQ a= Over I up to p rad minutes minutes pm p rad seconds secondsi I minutes I pm seconds I (34) (35) (36) (37) =E (38) (39) (40) (41) ,35,, = , 52,, =+= 1600 y 30,( IOO = I % o 49m I I I I 8 35 ] j ] I H I I 6 52 I ] ,,0,, -+=-E= =-i == [ I I I 3 26 I I 400 I 1 22 FIG. 2 CONICALWORKPIECE EXTERNALCONE 7

13 FIG. 3 CONICALWORKPIECE INTERNALCONE ~ L i BASICCONE 8

14 --i FIG. 5 ACTUALCONE L CONE FIG. 6 GENERALDEFINITIONS GENERATING ANGLE BASIC ANGLE 1 FIG. 7 ANGLESONCONES 9

15 1S 7615:2003 FORM TOLERANCE ZONE CONE DIAMETER E ZONE x. FIG. 8 LIMITCONES,CONEDIAMETER,TOLERANCEZONEANDSTRAIGHTNESSOF GENERATORTOLERANCEZONE FORM TOLERANCE TD ZONE O ON CONE CONE D TOLERA FtG.9 CONEDIAMETERTOLERANCEZONEANDROUNDESSTOLERANCEZONE FIG. 10 LIMITCONEANGLES ATa --z- 10

16 The parallel straight lines, shown in this figure, lie in plane 1. FIG. 11 ACTUALCONEANGLES &T 2 a+at A B c FIG. 12 POSITIONOFCONEANGLEWITHINTHECONEDIAMETERTOLERANCEZONE TD 7 TD T I A i I - - D min. Dm ax... _D min. D max. f t FIG. 13 CONEDIAMETERTOLERANCESPACEFORMED BY CONEDIAMETERTOLERANCE FIG. 14 ADMISSIBLECONEFROMDEVIATION RESULTINGFROMCONEDIAMETERTOLERANCE 11

17 I- a min.. +Aa T D min. I 4-J LT J 2 FIG. 15 ADMISSIBLELIMITCONE ANGLESRESULTINGFROM CONE DIAMETERTOLERANCE AT ~ AT 2 I L2 D FIG. 16 VARIATIONOFA 7 ~ WITHINRANGEOFCONE LENGTHWITHLIMITS OF LENGTHRANGE L, AND Lz 12

18 AT T SECTION (a) Actual cone diameter in the defined section has the maximum permissible AT size of cone diameter 77 f (b)actual cone diameter in TDs the defined section lies r= between the limit sizes of cone diameter SECTION (c) Actual cone diameter in the defined section has the minimum size of the cone diameter FIG. 17 CONESECTIONDIAMETERTOLERANCET~~ AND CONEANGLETOLERANCEAT -D. c1 FIG. 18 CONEANGLETOLERANCEA Tu OFA CONEDEFINEDBY ITSMEASURINGDIAMETERAND TNELONGITUDINALDIMENSIONSOFWHICHAREDEFINEDTHEMSELVESFROM THEPOSITIONOFTHEMEASURINGPLANE 13

19 ANNEX A (Clause 5.1) MAXIMUM CONE ANGLE DEVIATIONS RESULTING FROM THE CONE DIAMETER TOLERANCES, TDFOR 100 mm CONE LENGTH Range of Cone Diameters, mm Grades up to 3 Over 3 to 6 Over 6 to 10 Over 10to18 Over 18t030 Over 30t050 Over 50t080 I Aa, p rad I lto IT O IT I IT IT IT IT IT IT IT IT ITIO lti IT IT IT IT IT

20 1S 7615:2003 ANNEX A (Concluded) Range of Cone Diameters, mm Grades Over 80 to 120 Over 120to 180 Over 180t0250 Over250t0315 Over315 to400 Over400t050C Aa, p rad lto IT O IT I IT IT I IT IT IT IT IT IT IT ITll IT IT IT T IT NOTE For lengthsotherthan 100 mm, thevaluesgiven inthetablebemultiplied by 100/L, wherel istheconelengthin mill imetres.

21 Bureau of Indian Standards BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters in the country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed t~ the Director (Publication), BIS. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed periodically; a standard along with amendments is reaffirmed when such review indicates that no changes are needed; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standards should ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of BIS Catalogue and Standards: Monthly Additions. This Indian Standard has been developed from Dot: No. BP 20 (340). Amendments Issued Since Publication Amend No. Date of Issue Text Affected Headquarters: BUREAU OF INDIAN STANDARDS Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi Telegrams: Manaksanstha Telephones: , , (Common to all offices) Regional Offices: Telephone Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg NEW DELHI { Eastern : 1/14 C.I.T. Scheme VII M, V.I.P. Road, Kankurgachi , KOLKATA { , Northern : SCO , Sector 34-A, CHANDIGARH Southern : C.I.T. Campus, IV Cross Road, CHENNAI Western : Manakalaya, E9 MIDC, Marol, Andheri (East) , MUMBAI { , Branches : AHMEDABAD. BANGALORE. BHOPAL. BHUBANESHWAR. COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. LUCKNOW. NAGPUR. NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANANTHAPURAM. VISAKHAPATNAM. { { , , Printed at Simco Printing Press, Delhi