इंटरनेट मानकDisclosure 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. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न' 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 11668 (1985): Technical drawings - Simplified representation of centre holes [PGD 24: Drawings] “!ान $ एक न' भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह” है” ह Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” . . IS : 11668 ._.^_.Srmplified ‘epresentation of centre holes ’ issued by the International Organization for Standardization ( IS0 I._. . The reference of ISO’ 6.229’335 : 003. INDIAN SIANUAi+US INS I II U I ILJN MANAK BHAVAN.411 indicated in designation should be read as IS : 11668 ..1982 ( Reaffirmed 2005 ) Indian Standard Is1 1 ._. attention is especially drawn to the following: Wherever the words ’ International Standard ’ appear.. .1977 Specification for centre drills Type A ( first revision ) (Technically equivalent) IS0 2540-l 972 IS : 67091977 Specification for centre drills Type l3 ( first revision ) ( Technically equivalent ) IS0 2541-l 972 IS : 6710-1977 Specification for centre drills Type R ( first revisiorl ) (Technically Equivalent i IS0 3098 l-1974 IS : 9609 ( Part 1 )-1983 Lettering on technical drawings: Part 1 English lettering ( firsi revision ) ( Identical ) IS0 6428-l 982 lS : 101641985 Requirements to execute techni- cal drawings for microcopying ( first revision ) ( Identical ) Adopted 1 November 1985 @ March 1987. was adopted by the Indian Standards Institution on the recommendation of the Drawings Sectional Committee and approvafof the Mechanical Engineering Division Council. --.._. they should be read as ’ Indian Standard ‘._.p_ I I TECHNICAL DRAWINGS .IS0 6411..SIMPLIFIED REPRESENTATION OF CENTRE HOLES National Foreword This Indian Standard is identical with IS0 641 I-1982 ’ Technical drawings .1985 UDC 744’43 : 621 ._C. ISI Gr 3 I I .1975 IS : 6708._. referring to this standard. 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 . Cross References international Standard Corresponding Indian Standard IS0 128-l 982 IS : 10714-1983 General ~principles of present- ation on technical drawings ( Identical ) IS0 866.62 IS0 6411 . In the adopted standard certain terminology and conventions are not identical with those used II? Indian Standard..-_--^ .^_. a) centre hole is required on the finished part.IS : 11668 . Centre drik for centre holes with radius form - Type R. Centre drills for centre holes with protecting chamfers . 1) At present at the stage of draft.1985 IS0 6411 . three different requirements may be defined on technical drawings for the form and size of centre holes. Simplified IS0 6428. Requirements for micro- representation of centre holes may be used particularly when it copying. 1) is not necessary to show the exact form and size and where the designation of standardized centre holes is sufficient for infor- mation. c) centre hole shall not exist on the finished part. Centre drills for centre holes without protecting namely : chamfers . a . This International Standard specifies the simplified represen- tation of centre holes and their designation. IS0 2540. Type A. Type 6. 3 Indication on drawings 2 References 3.1982 1 Scope and field of application IS0 309811. Technical drawings .1 Requirements IS0 128. b) centre hole can be accepted on the finished part. Technical drawings . ~General principles of presen- tation. IS0 866. Lettering . IS0 2541. Part 1 : Current& used characters. Generally. Technical drawings . but is not a fundamental requirement. 3 . 4 Interpretation of vindication The desrgnation of the centre hole itself consists of The relationship between the various designations used to specify the centre holes. and dimensions depending on the centre drill used are shown in table 2.5/8 The designation of centre~holes is dependent on the drill and may be indicated with refarence either to an International Stan- dard or to any other standard dealing with this subject. Representation and designation of centre holes on drawings Dimensions in millrmetres Requirement Repreeentatian Designation Centre hole is required on the rinished part Centre hole may remain on the finished part Centre hde shatl not exisf on the finished part . type B with d = 2. . the letter for the type (I% A or 6).51'1 3 II For the machining of such a centre hole. a drill with d = 2. to . SO 6411-B2.2 Simplified representation -. a reference to this International Standard. the end face of a shaft are shown in column 2 of table 1. are given in annex A Table 1 . given designations.5 mm and D3 = 8 mm may be indicated on the drawing as : 3. Further details specifying the dimensions of the centre hole.5 and d. the dimensions represented by the . Example : a centre holet).___. be indicated preferably on the drawings. the outside countersink centre hole diameter D.3 Designation of centre holes IS0 8411-B 2. IS :11668-1985 IS0 6411 -1982 3. = 10 according to IS0 2540 is used. The symbols representing centre holes and their application to The two values are separated by a solidus. the prlot arameter d. IS :I1668 -1985 IS0 6411 .5 4=8 l For dimension I.lV6.5/8 (centre drill according IS0 2540) c/=2. interpretation of the designation Dimensions in milllmetres I Type of D_esignation (examples) Interpretation of the designation centre hole R with radius form IS0 6411-R 3.5 with protecting 6 chamft _~.1982 Table 2 .15 D.82. It should not he less than i 4 .7 i _ without A chamfer protecting _~. 6411. see annex A l * Dimension I depends on the length of the centre drill.5 t* L-4 centre drill according IS0 866) tl d=4 L I** D2= 8.7 entre drill according to IS0 2541) d = 3. 6411-A 418.= 6. 0 21.1982 Annex A Dimensions for centre holes type R.2 13.5) 1. nom.25 1.5 (0.7 1.6 3.8) 1. .5 35 (5 0) 10.15 6.20 1 a.8 6.00 7.631 1.3 1.7 6.8 2.2 8 2.60 4.70 2.1 1. ref “0”) ref I 10.70 t 0. A and B The dimensions which are necessary to specify a centre hole are shown in table 3 Table 3 .9 3 15 0.o 4.5 8.4 16 6.5 12.12 2.25) 2.5 5.2 21. DI 4 I r* i nom.35 1.65 2~65 l.35 3.9 (1.3 13.30 2.20 55 18 (8.7 NOTE .32 06 (0.50 3.0 8. A B d according to IS0 2641 according to IS0 866 accordtnq to IS0 2540 nom.12 0.4 5 14 2.06 0.8 10 2.0 17.8 4.6 10.1985 IS0 6411 .25 4. Dimensions of preferred centre holes Tvw R .01 17.0 224 28 10.l 4 1. Sizes in brackets should be avoided whenever possible.0 2.2 3.3 5. IS : 11668 . 1.2 Proportions International Standard with those of the other inscriptions on the drawing (dimensions. shall he drawn in accordance with the figure.1.5 0. Figure Reprography Unit.l General requirements B.) the following rules The symhol and its complements shown in area a (see 8.8 line thickness (~‘1.7 mm.4 2 B. - Line thickness for symbols (d’ ) 0.l.1985 .2 lettering (d) Height H1 5 7 10 14 20 28 It is recommended that this spacing he not less than 0. IS0 6411 .5 0.1 The symbols shown in the table shall he inscribed with The range of sizes to he used for the symbols and additional a line thickness (d’ ) equal to 1 /lO of the height (h) of the letter. tolerances. ISI. India 6 . indications is given in tahle 4. etc. B.7 1 1.1. in millimetres B. height (h) and type of lettering as us&d for the dimensions in the relevant drawing.7 1 1. ing used for the dimensions in the relevant drawing.35 0. see 8.5 5 7 10 14 20 IS0 309811. New Delhi. Table 4 .1982 Annex B Proportions and dimensions af symbols In order to harmonize the sizes of the symbols specified in thiq B.3 Dimensions B. and in accordance with Height of_numerals and capital letters (h) 3.4 2 2. Dimensions.IS : 11668 .3 The minimum spacing hetween adjacent lines shall be ______~_ Line thickness for in accordance with IS0 128 or IS0 6428.3) shall he ohserved.2 The numerals and capital letters used for the additional Line thickness for specifications of centre holes shall be inscribed with the same outlines of an item Ih) 0.