摘要 |
A two zoned grinding wheel is disclosed having a lower section or zone composed of bonded abrasive grain and an upper zone or section made up of bonded particles of a material that is softer than the abrasive grain and therefore less abrasive. The wheel is especially suitable for being held in clamps or a chuck when being used, with the clamps or chuck contacting the wheel on the upper less abrasive section thus greatly reducing wear on said clamp or chuck. |