Guides & Toolkits

ABRASIVE (GRINDING) WHEELS 4 330-ARB-01-IGDO © 2019, Workplace Safety & Prevention Services (WSPS) 1 877 494 WSPS (9777) | 905 614 1400 | www.wsps.ca Figure 2 – The Ring Test ANSI B7.1-2017 Standard Requirements Explanatory Information (Not Part of Standard) Figure 39 Figure 40 Tap the wheel gently with a nonmetallic implement such as a wooden screw driver handle for light wheels and a wooden mallet for heavy wheels. The best spot to tap a wheel for the ring test is about 45 degrees either side of the vertical center line and about 1 or 2″ from the periphery. (See figures 39 and 40.) If struck directly along the vertical center line, the ring, even in a sound wheel, is sometimes muffled and may give the erroneous impression that the wheel is cracked. This is especially true with large wheels which are supported on the floor when conducting this test. (See figure 40.) Also, it is sometimes no- ticeable when the wheel is suspended from the hole. It is recommended that the test be repeated after rotating the wheel 45 degrees to the right or left. Apply this ring test immediately before mounting either a new or used wheel on a machine. Comparison of the sound with other wheels of the same lot and specification will allow rejection of any wheel with a suspiciously different ring. large, thick wheels may be given the ring test by striking the wheel on the periphery rather than the side of the wheel. The sound of an undamaged wheel will be a clear tone. If cracked, there will be a dead sound and not a clear ring and the wheel shall not be used. Limitation: Wheels must be dry and free of loose material such as sawdust or swarf when applying the ring test, otherwise the sound may be deadened. The ring test is not applicable to certain wheels because of their shape or size. examples are: 1. small wheels (4″ diameter and smaller); 2. plugs and cones; 3. mounted wheels; 4. segments; 5. plate-mounted wheels; 6. inserted nut and projecting stud disc wheels. E 6.1.1.3 Vibration test The vibration test can be used either in lieu of or in conjunction with the ring test. The test is applicable to all bond types and is not impaired by ambient noise. 6.1.1.3 Vibration test The vibration test is based on the way that loose sand or similar material is distributed on the side of a wheel when the wheel is vibrating. Copyrighted material licensed to natasha galarraga on 2019-09-09 for licensee's use only. No further reproduction or networking is permitted. Distributed by Clarivate Analytics (US) LLC, www.techstreet.com. Source: ANSI B7.1-2017, Figure 39 and 40 The Vibration Test The vibration test assesses how dry sand moves on the side of a vibrating wheel. If the wheel is in good condition, the sand will remain evenly spread out over the entire surface of the wheel. Use the vibration test on all bonded wheels. Unlike the ring test, the vibration test can be performed in noisy areas. Here's how the vibration test works:  1. Set the abrasive wheel on its side on a test fixture. 2. Coat the wheel with a thin layer of fine, dry sand. 3. Turn on the test fixture to get the wheel to gently vibrate. 4. Watch the grains of sand as the wheel vibrates. If the sand moves away from an area of the wheel, this indicates a crack. If the sand remains evenly distributed on the wheel, the wheel is fine. 5. Repeat the above steps for the other side of the wheel. The ring and vibration tests cannot absolutely guarantee the condition of a wheel. For this reason, all persons must stand clear when a grinding wheel is started. A defective wheel is most likely to shatter at start-up. WSPS.CA

• Cover