English to Japanese Tech/Engineering Automotive / Cars & Trucks �Ԃ̓h���̌����i�‚�o���j�H��

The counterweight is a half-moon shaped piece of metal attached to the rotating shaft of the tool. This smooths out the random orbit action by providing a counter balance to the elliptical orbit of the rotating ***backing pad***. If you change the pad size you must also change the counterweight or suffer unnecessary vibration and possible damage to the tool.