1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-20984-1 SANS 10079:2008Edition 2.1Any reference to SABS 079 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 No
4、vember 2002)SOUTH AFRICAN NATIONAL STANDARD The use, care, and protection of grinding wheels Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 100
5、79:2008 Edition 2.1 Table of changes Change No. Date Scope Amdt 1 2008 Amended to change the designation of SABS standards to SANS standards and to update the definition of “acceptable“. Acknowledgement Standards South Africa wishes to acknowledge the valuable assistance derived from the American St
6、andard ANSI B7.1-1970 “The use, care, and protection of abrasive wheels”. Foreword This South African standard was approved by National Committee StanSA TC 5120.07, Handheld non-electrical tools for general purpose use, in accordance with procedures of Standards South Africa, in compliance with anne
7、x 3 of the WTO/TBT agreement. This document was published in March 2008. This document supersedes SABS 10079:1975 (edition 2). A vertical line in the margin shows where the text has been technically modified by amendment No. 1. Preface Basic to a proper understanding of this standard is a thorough k
8、nowledge of the nature and characteristics of grinding wheels, the grinding machines on which they are used, and the safety and protective devices which should be used to limit, if not eliminate, injury or damage in case of accidental wheel breakage. Constant educational programmes at all levels are
9、 the best means of avoiding those unforeseen conditions or circumstances which may result in an industrial accident. As the workers knowledge increases, the possibility of accidental injury or damage is reduced or eliminated. The standard outlines the best known practices, tests, and safety devices
10、for the protection of all personnel and equipment from injury or damage in case of accidental wheel breakage and is specifically dedicated to vigilant safety practice and education. SANS 10079:2008 Edition 2.1 1 Contents Page Acknowledgement Foreword Preface 1 Scope . 3 2 Definitions 3 3 Handling, s
11、torage, and inspection . 4 4 General machine requirements 6 5 Safety guards . 13 6 Flanges 27 7 General recommendations on mounting 33 8 General operating rules . 35 Appendix A Types of grinding wheels . 37 SANS 10079:2008 Edition 2.1 2 This page is intentionally left blank SANS 10079:2008 Edition 2
12、.1 3 The use, care, and protection of grinding wheels 1 Scope This code of practice covers recommendations for the safe use of grinding wheels (excluding natural sandstone wheels). Recommendations for the proper storage, handling, and inspection of wheels are included, as well as requirements coveri
13、ng safety guards, flanges, and the mounting of wheels. NOTE The type numbers designating various shapes of grinding wheels are listed in appendix A. 2 Definitions 2.1 For the purposes of this code of practice the following definitions shall apply: cutting-off the cutting-off or parting of any compon
14、ent or part of a work piece cylindrical grinding the grinding of the outer surface of any work piece that is held by a chuck or collet and rotated about an axis flanges collars, discs, or plates between which grinding wheels are mounted grinding disc a wheel affixed to an adaptor plate and intended
15、for grinding on a side surface only grinding wheel a cutting tool of the rotating type consisting of abrasive particles bound into a particular shape by a suitable bonding material inorganic bonded wheels wheels that are bonded by means of inorganic materials such as clay, glass, porcelain, sodium s
16、ilicate, magnesium oxychloride, or metal. (Wheels bonded with clay, glass, porcelain, or related ceramic materials are better known as “vitrified bonded wheels“.) internal grinding the precision grinding of an internal surface (e.g. the sides of a hole) in a work piece offhand grinding the grinding
17、of any work piece that is held in the operators hand organic bonded wheels wheels that are bonded by means of an organic material such as resin, rubber, shellac, or other similar bonding agent SANS 10079:2008 Edition 2.1 4 portable grinding a grinding operation in which the grinding machine is hand
18、held and may be easily moved from one position to another precision grinding grinding operations performed by machines capable of finishing work parts to specified dimensions and finish requirements reducing bush an insert or space used to so reduce the diameter of the hole in a grinding wheel that
19、it can be correctly mounted on a spindle of smaller diameter reinforced wheels an organic bonded grinding wheel in which fabric or filament material is incorporated to increase the strength. (These wheels are distinct from wheels that are reinforced with steel rings, steel cup backs, or wire or tape
20、 winding.) safety guard an enclosure designed to effectively restrain the pieces of a grinding wheel should accidental breakage occur spindle speed the number of revolutions that a spindle makes in one minute when running free steel ring a ring moulded into certain organic bonded wheels to increase
21、rigidity and to retain the pieces of the wheel should accidental breakage occur surface grinding the precision grinding of a plane surface tape or wire winding reinforcing used on the periphery of cylinder or cup wheels to retain the pieces of the wheel should accidental breakage occur threaded bush
22、 an internally threaded bush securely cemented or moulded into a grinding wheel wheel speed the surface speed, expressed in metres per second and computed from the free running speed of the machine spindle 3 Handling, storage and inspection 3.1 Handling Handle all grinding wheels with care to preven
23、t damage. Observe the following rules: a) avoid dropping or bumping grinding wheels; b) do not roll wheels; c) for the transportation of wheels that cannot be carried by hand use only vehicles that will provide proper support for the wheel. SANS 10079:2008 Edition 2.1 5 3.2 Storage Provide suitable
24、racks, bins, or drawers to store the various types of wheels used. Do not store wheels under conditions subject to a) high humidity; b) exposure to water or other liquids; or c) freezing temperatures. Arrange wheel storage to allow selection of wheels and their removal without disturbance or damage
25、to other wheels. 3.3 Inspection 3.3.1 General Immediately after unpacking, inspect all wheels to make sure that they have not been damaged during handling, shipping, or other operations. As an added precaution, it is advisable to submit all wheels to the “ring test“ (see 3.3.2), when wheels that are
26、 sound and undamaged will give a clear metallic ring while cracked wheels will emit a dead sound. It should be noted that organic-bonded wheels do not emit the same clear metallic ring as do vitrified bonded and silicate bonded wheels and that most reinforced wheels do not ring at all. Damaged wheel
27、s shall not be used. 3.3.2 Ring test Wheels must be dry and free from sawdust and other packing material when tested. Suspend light wheels on a finger or suitable pin inserted through the centre hole. Support heavy wheels in a vertical position on a clean hard floor. Use a light non-metallic impleme
28、nt such as a screwdriver handle to test light wheels and a wooden mallet to test heavy wheels. Tap the wheels at points about 45 on either side of the vertical centre line and about 25 or 50 mm from the periphery as indicated by the spots in figures 1 and 2. Then rotate the wheel through 180 and rep
29、eat the test. SANS 10079:2008 Edition 2.1 6 Suspend on small pin or finger inserted through hole Support on clean hard floor Figure 1 Tapping points for light wheels Figure 2 Tapping points for heavy wheels 4 General machine requirements 4.1 General It shall be the machine manufacturers responsibili
30、ty to design, and the users responsibility to maintain, grinding machines so as to ensure safe operating conditions. 4.2 Safety guards Grinding machines shall, when relevant, be equipped with safety guards that comply with the appropriate requirements laid down in section 5. 4.3 Power Ensure that gr
31、inding machines are provided with motors of sufficient power to maintain the rated spindle speed under conditions of normal operation. 4.4 Exhaust provision Ensure that stationary machines used for dry grinding have provision for connection to an exhaust system. SANS 10079:2008 Edition 2.1 7 4.5 Dia
32、meter of spindle Spindle diameters for wheels of various sizes shall conform to the minimum requirements given in table 1. NOTE Wheels larger than those specified by the machine manufacturer shall not be used on a machine. 4.6 Flanges Grinding machines shall, when relevant, be equipped with flanges
33、that comply with the appropriate requirements listed in section 6. Proper selection, use, and maintenance of flanges are essential factors in the safe use of grinding wheels. 4.7 Work rests Work rests, of rigid construction and readily adjustable to compensate for wheel wear, shall be provided to su
34、pport the work piece on offhand grinding machines. To prevent the work piece from being jammed between the wheel and rest, keep the work rest closely adjusted relative to the wheel and ensure that the width of the opening does not exceed 3 mm. Clamp the rest securely after each adjustment. No adjust
35、ment shall be made while the wheel is in motion. 4.8 Wheel diameter limits Grinding machines shall be provided with means of limiting the maximum diameter of wheel that can be mounted. In the case of a single speed machine the safety guard is satisfactory for this purpose. On variable speed machines
36、 the speed shifting device shall be mechanically or otherwise connected to a diameter limiting device to prevent the engagement of a spindle speed higher than that recommended for the size of wheel which is mounted. 4.9 Hand of spindle thread When wheels are mounted by means of a central spindle nut
37、, the hand of the thread shall be such that the nut will tend to tighten as the spindle revolves; i.e. to remove the nut, it must be turned in the direction that the spindle revolves when the wheel is in operation. 4.10 Length of spindle thread When wheels are mounted by means of a central spindle n
38、ut and flanges, the following requirements shall be met: a) Spindles shall be of sufficient length to accommodate a full nut. b) The threaded part shall extend well inside the loose flange but not more than halfway into the hole in the wheel. 4.11 Spindle size (see 4.5) Grinding wheels shall fit fre
39、ely on the spindle and remain free under all grinding conditions. To achieve this the size of the spindle or wheel mount shall be nominal plus zero minus 0,05 mm. SANS 10079:2008 Edition 2.1 8 Table 1 Minimum nominal diameter of machine spindles for overhung wheels of various diameters and thickness
40、es operating at speeds up to 48,0 surface metres per second* 1 2 3 4 5 6 7 8 9 10 11 12 13 Nominal diameter of spindle mm For nominal wheel thickness Nominal diameter of wheel mm mm Less than 6 6 10 13 20 25 32 40 50 65 80 100 80 100 125 6 10 10 6 10 10 10 10 10 10 10 13 10 10 13 10 13 13 13 13 13 1
41、3 13 150 180 200 13 13 13 13 13 13 13 13 13 13 13 13 13 13 16 13 13 16 13 16 16 13 16 16 16 16 20 20 20 20 20 20 25 20 25 25 250 300 350 16 16 20 16 20 20 16 20 20 16 20 20 20 20 25 20 20 25 20 20 25 20 25 25 20 25 25 25 25 32 32 32 32 32 32 40 400 450 500 25 25 25 25 25 25 25 25 25 25 25 25 32 32 3
42、2 32 32 40 32 32 40 32 32 40 32 32 40 32 40 40 40 40 40 40 50,8 50,8 600 750 900 25 25 40 25 40 50,8 25 40 50,8 25 40 50,8 32 40 50,8 40 40 50,8 40 50,8 50,8 40 50,8 50,8 40 50,8 50,8 40 50,8 50,8 50,8 50,8 76,2 50,8 50,8 76,2 * For speeds exceeding 48,0 surface m/s and for wheels with heavy mountin
43、gs (such as bolted-on abrasive discs), the spindle sizes shown in this table are usually not adequate. As the proper spindle size is dependent upon various factors (such as general design of the machine, type of bearings, and quality of materials and workmanship) a simple table is not practicable fo
44、r such cases. 4.12 Mounting of threaded-hole wheels Machines on which threaded-hole wheels are mounted shall be provided with spindles that are so threaded as to allow the wheel to be screwed firmly against the back flange (see figures 3 and 4). The back flange shall be flat, unrelieved, securely fi
45、xed, and square to the spindle axis. It shall also be of sufficient diameter to ensure proper support for the wheel. The hand of the thread shall be such that to remove the wheel, the wheel must be turned in the same direction as that in which it rotates when in use. When threaded-hole wheels are of
46、 cone or plug shape with blind holes, the length of the spindle shall be such that there is adequate clearance between the end of the spindle and the bottom of the hole. SANS 10079:2008 Edition 2.1 9 Correct Incorrect Figure 3 Mounting of cones with threaded bush Correct Incorrect Figure 4 Mounting
47、of cup wheels with threaded bush SANS 10079:2008 Edition 2.1 10 Figure 5 Mounting of inserted nut type of grinding disc 4.13 Mounting of grinding discs Machines on which grinding discs of the inserted nut type (see figure 5) are mounted shall be provided with an adaptor plate of approximately the sa
48、me diameter as the disc and of sufficient thickness to provide proper support. The minimum thicknesses of adaptor plates for disc grinders shall be as given in table 2. SANS 10079:2008 Edition 2.1 11 Table 2 Minimum thickness of adaptor plates for disc grinders 1 2 Diameter of grinding disc, D Min.
49、thickness mm mm 200 350 450 D D D 35045065013 16 19 650 900 1 000 D D D 9001 0001 80022 25 28 The mounting face of the adaptor plate shall be true, flat, and at right angles to the machine spindle. Screw holes in adaptor plates shall be accurately located to match the inserted nuts in the wheel and large enough to prevent binding of the screws. See figure 6 for a detail of the inserted nut type of engagement. Dimension X shall be uniform for all holes so that the screws will be interchangeable. Screws shall be long enough to properly engag
