Vitrified Grinding Wheels
Initial Operation of a Grinding Wheel
The Ring Test
The Ring Test should be carried out immediately before mounting a new or used grinding wheel. The wheel should be lightly tapped to the right and to the left of the vertical centerline with a non-metallic hammer. Light wheels should be held on the finger or on a mandrel, heavier wheels tilted on their edge on the floor. The wheel must be dry for the ring test. A crack-free wheel will emita clear ringing sound; a damaged wheel will sound dull. Resin bonded wheels do not emit the same clear metallic ring as vetrified wheels.
Flange screws must be tightened in a criss-cross
sequencesimilar to the illustration
Mounting of Grinding Wheels
The condition and the design of flanges have considerable effects on the final grinding results. Flanges must be free of damage as this may lead to imbalanced wheels. Damage to flages may also exert uneven pressure on the grinding wheels and considerably reduce their resistance to breakage. When selecting grinding machine flanges, please refer to the revelant national recommendations (ANSI B7.1-1988; Section 5, FLANGES; or ISO/DP 666 or DIN 6375).
Blotters (paper or plastic) must always be used when between each flange and the abrasive wheel surface to ensure uniform flange pressure. Blotters must cover the entire flange contact area.
Attention: Torque wrenches should be used to tighten screws on multiple screw flanges. As per ANSI B7.1-1988, Chapter 6.10.2, applied torque should not exceed 20 foot pound (27 Newton metres) unless greater torque is recommended by the wheel manufacturer. In the case of wheel width < 0.75 in. (<20 mm) and wheels with induced porosity, lower torque may be necessary.
If unsure, please consult a Winterthur engineer
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