IS 15297 : 2013 ISO 6103 : 2005 (Superseding IS 13068 : 1991) Hkkjrh; ekud ckafMM vi?k"khZ mRikn lqiqnZ f?klkbZ ifV~V;ksa esa — vlra yq u LFkfS rd ijh{k.k — (igyk iqujh{k.k) Indian Standard BONDED ABRASIVE PRODUCTS — PERMISSIBLE UNBALANCE OF GRINDING WHEELS AS DELIVERED — STATIC TESTING ( First Revision ) ICS 25.100.70 © BIS 2013 B U R E A U O F I N D I A N S T A N D A R D S MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 February 2013 Price Group 4 Abrasives Sectional Committee, PGD 09 NATIONAL FOREWORD This Indian Standard (First Revision) which is identical with ISO 6103 : 2005 ‘Bonded abrasive products — Permissible unbalance of grinding wheels as delivered — Static testing’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Abrasives Sectional Committee and approval of the Production and General Engineering Division Council. This standard was originally published as IS 13068 : 1991 ‘Bonded abrasive products — Static balancing of grinding wheels — Testing’. The Committee then decided to adopt IS 15297 : 2003 ‘Bonded abrasive products — Permissible unbalances of grinding wheels as delivered — Testing’ identical with ISO 6103 : 1999 under dual numbering system to make pace with the latest development that have taken place at international level. This standard is now being revised to harmonize it with the latest version of ISO 6103 : 2005. This standard supersedes IS 13068 : 1991. After publication of this standard IS 13068 : 1991 shall be treated as withdrawn. The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminology and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following: a) Wherever the words ‘International Standard’ appear, referring to this standard, they should be read as ‘Indian Standard’. b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker. . In this adopted standard, reference appears to certain International Standards for which Indian Standards also exist. The corresponding Indian Standards, which are to be substituted in their respective places, are listed below along with their degree of equivalence for the editions indicated: International Standard Corresponding Indian Standard Degree of Equivalence ISO 603-1 : 1999 Bonded abrasive IS/ISO 603-1 : 1999 Bonded Identical products — Dimensions — Part 1: abrasive products — Dimensions: Grinding wheels for external Part 1 Grinding wheels for external cylindrical grinding between centres cylindrical grinding between centres ISO 603 -2 : 1999 Bonded abrasive IS/ISO 603-2 : 1999 Bonded do products — Dimensions — Part 2: abrasive products — Dimensions: Grinding wheels for centreless Part 2 Grinding wheels for centreless external cylindrical grinding external cylindrical grinding ISO 603-3 : 1999 Bonded abrasive IS/ISO 603-3 : 1999 Bonded do products — Dimensions — Part 3: abrasive products — Dimensions: Grinding wheels for internal Part 3 Grinding wheels for internal cylindrical grinding cylindrical grinding (Continued on third cover) IS 15297 : 2013 ISO 6103 : 2005 Indian Standard BONDED ABRASIVE PRODUCTS — PERMISSIBLE UNBALANCE OF GRINDING WHEELS AS DELIVERED — STATIC TESTING ( First Revision ) 1 Scope This International Standard specifies the maximum permissible values of unbalances for various grinding wheels of ISO 603-1 to ISO 603-9 and ISO 603-12 to ISO 603-16 in the as-delivered condition, with an outside diameter D (cid:33) 115 mm and maximum operating speed vs W 16 m/s. It also specifies the method for measuring the unbalance and the practical method for testing whether a grinding wheel is acceptable or not. This International Standard is applicable to bonded abrasive grinding wheels in the as-delivered condition. This International Standard is not applicable to (cid:127)(cid:3) diamond, cubic boron nitride or natural stone grinding wheels, or to (cid:127)(cid:3) centreless control wheels, lapping and disc wheels, ball wheels or glass grinding wheels. NOTE 1 The values given refer to the grinding wheel itself, independent of any unbalance which may exist in the balancing arbor or in the means of fastening it to this arbor. These various elements, together with the flanges or hub-flanges, are assumed to be balanced, homogeneous and free from geometrical defects. NOTE 2 The effects of unbalance are basically (cid:127)(cid:3) additional stresses on the arbor, the machine and its mounting, (cid:127)(cid:3) excessive wear of the bearings, (cid:127)(cid:3) vibration prejudicial to the quality of machining and increased internal stresses in the grinding wheel, and (cid:127)(cid:3) increased operator fatigue. 2 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 603-1, Bonded abrasive products — Dimensions — Part 1: Grinding wheels for external cylindrical grinding between centres ISO 603-2, Bonded abrasive products — Dimensions — Part 2: Grinding wheels for centreless external cylindrical grinding ISO 603-3, Bonded abrasive products — Dimensions — Part 3: Grinding wheels for internal cylindrical grinding 1 IS 15297 : 2013 ISO 6103 : 2005 ISO 603-4, Bonded abrasive products — Dimensions — Part 4: Grinding wheels for surface grinding/peripheral grinding ISO 603-5, Bonded abrasive products — Dimensions — Part 5: Grinding wheels for surface grinding/face grinding ISO 603-6, Bonded abrasive products — Dimensions — Part 6: Grinding wheels for tool and tool room grinding ISO 603-7, Bonded abrasive products — Dimensions — Part 7: Grinding wheels for manually guided grinding ISO 603-8, Bonded abrasive products — Dimensions — Part 8: Grinding wheels for deburring and fettling/ snagging ISO 603-9, Bonded abrasive products — Dimensions — Part 9: Grinding wheels for high pressure grinding ISO 603-12, Bonded abrasive products — Dimensions — Part 12: Grinding wheels for deburring and fettling on a straight grinder ISO 603-13, Bonded abrasive products — Dimensions — Part 13: Grinding wheels for deburring and fettling on a vertical grinder ISO 603-14, Bonded abrasive products — Dimensions — Part 14: Grinding wheels for deburring and fettling/ snagging on an angle grinder ISO 603-15, Bonded abrasive products — Dimensions — Part 15: Grinding wheels for cutting-off on stationary and mobile cutting-off machines ISO 603-16, Bonded abrasive products — Dimensions — Part 16: Grinding wheels for cutting-off on hand held power tools 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 unbalance product of the radius, in millimetres, and mass, in grams, expressed in grams multiplied by millimetres 3.2 intrinsic unbalance of a grinding wheel U i product of the mass m of the grinding wheel and the distance e between its centre of mass G (centre of 1 gravity) and the axis O of its bore See Figure 1. 2 IS 15297 : 2013 ISO 6103 : 2005 U (cid:32) m (cid:152) e i 1 Figure 1 3.3 measured unbalance U c product of a mass, m , affixed to the grinding wheel to balance it and the distance between the centre of mass 2 (G ) (centre of gravity) of the mass m and the axis O of the grinding wheel bore m2 2 See Figure 2. NOTE In practice, this distance is equal to the radius r of the grinding wheel. U (cid:32) m (cid:152) r c 2 Key 1 mass m 2 Figure 2 4 Permissible unbalance, U a On the basis of experience, the maximum permissible unbalance U is determined using a mass m (cid:32) U /r, a a a such that m (cid:32)k m (1) a 1 3 IS 15297 : 2013 ISO 6103 : 2005 where r is the radius of the grinding wheel, in millimetres; m is the mass whose centre is located on the circumference of the grinding wheel, in grams; a m is the mass of the grinding wheel, in grams; 1 k is a coefficient which depends on the nature and usage of the grinding wheel. The values of k are given in Table 1 and the values of m , as a function of m and k, are shown in Figure 5. a 1 The values of k have been selected on the basis of experience so that the resulting unbalance allows for normal usage of the grinding wheel. 5 Measuring intrinsic unbalance Place a balancing arbor through the bore of the grinding wheel to hold its mid-plane in a vertical position. For straight wheels or wheels of similar shape, the wheel is free-standing; wheels of other shapes may be supported using suitable flanges. Rest the balancing arbor on two parallel horizontal bevelled guide-bars or cylindrical bars (see Figure 3), or on a balancing stand consisting of two pairs of overlapping, freely rotating, steel discs (see Figure 4), so that the grinding wheel attains an equilibrium position with minimum friction. Alternative: the two bevelled guide-bars may be replaced by two cylindrical bars. Figure 3 Figure 4 4 IS 15297 : 2013 ISO 6103 : 2005 The clearance between the balancing arbor and the bore of the grinding wheel shall not exceed 0,4 mm. The arbor and the supports (guide-bars, bars or discs) shall have an adequate surface hardness and an appropriate surface condition to minimize friction. When the grinding wheel attains the equilibrium position, its centre of mass is then as low as possible. In this position, mark the upper peripheral point of the grinding wheel. Rotate the grinding wheel through 90(cid:113) to bring this mark into the horizontal plane for the arbor axis. Determine the mass m which, when affixed to the periphery of the grinding wheel at the mark, maintains the 2 grinding wheel in equilibrium. The amount of unbalance thus introduced, U (cid:32) m (cid:152) r, is equal and opposite to c 2 the intrinsic unbalance of the wheel. The value of the mass m is used to determine the intrinsic unbalance of the wheel using the following 2 formula: U (cid:32) U (cid:32) m (cid:152)r (2) i c 2 6 Checking intrinsic unbalance 6.1 Verification and acceptance Verify the intrinsic unbalance using the method according to Clause 5. A grinding wheel is only acceptable if its intrinsic unbalance U is less than or equal to the permissible i unbalance U , i.e. a Ui u Ua (3) The testing is done with a mass U m (cid:32) a (4) a r 6.2 Determination of m a From Table 1, determine the coefficient k by reading off the value according to the various parameters related to the grinding wheel and its application. Figure 5 then gives the values of the mass m , in grams, as a function of the mass m of the wheel, in grams, a 1 and the coefficient k. 6.3 Acceptance testing of the grinding wheel With the grinding wheel mounted in accordance with Clause 5, place a mass m as determined in 6.2 on the a periphery of the grinding wheel at the mark. If the wheel remains stationary or rotates so that the mark is at the bottom, the grinding wheel is accepted; otherwise, it is rejected. 5 IS 15297 : 2013 ISO 6103 : 2005 Table 1 — Values of the coefficient k for bonded abrasive products Dimensions Coefficient k for maximum operating speed Type of D T v Grinding bonded s Type of machine method abrasive product m/s mm mm 16 u vs u 40 40 (cid:31) vs u 63 63 (cid:31) vs u 100 115 (cid:31) D u 150 — 0,40 0,32 0,25 Types 150 (cid:31) D u 180 — 0,40 0,32 0,20 Grinding 1/4/27/28/35 (deburring, Hand-held grinding and 36 T u 6 0,40 0,32 0,20 fettling and machines D (cid:3)(cid:33) 180 snagging) T (cid:33) 6 0,32 0,25 0,20 Types 6 all dimensions 0,40 0,32 — and 11 Stationary grinding Grinding machines, swing Types (deburring, frame grinding 1/2/35 all dimensions 0,63 0,50 0,40 fettling and machines and other and 36 snagging) grinding machines High-pressure Stationary grinding Type 1 all dimensions 0,8 grinding machines Grinding 125 (cid:31) D u 300 0,25 0,20 0,16 – precision 300 (cid:31) D u 610 0,32 0,25 0,20 grinding – external Stationary grinding all cylindrical All types machines dimensions grinding D (cid:3)(cid:33) 600 0,40 0,32 0,25 – surface grinding – sharpening Hand-held cutting- Types 41 115 (cid:31) D u 400 — 0,40 0,32 0,20 off machines and 42 Cutting-off Stationary cutting- Types 41 D u 300 — 0,50 0,40 0,32 off machines and 42 D (cid:3)(cid:33) 300 — 0,63 0,50 0,40 6 IS 15297 : 2013 ISO 6103 : 2005 Key Y value of m , in grams a X mass of wheel m , in grams 1 a See example. EXAMPLE For a straight grinding wheel for precision grinding, of outside diameter D (cid:32) 762 mm and mass m (cid:32) 68 000 g used on a stationary machine at a maximum operating speed v (cid:32) 60 m/s, the coefficient k (cid:32) 0,32 (see 1 s Table 1) and the maximum permissible mass m (cid:32) 83 g. a Figure 5 7