1. : diamond grinding for machining of glass: glass thickness, jade, jade, agate, pearls and other building materials.<br> 2. the : electric drill speed 3600 rpm, bench drill and machine speed in 6000 ~ 10000. The water must be so as to achieve the best effect.<br> 3. About how to the explanation: if the material thickness of 8mm, the appropriate 8mm diamond grinding .<br> Specification:<br> Shaft diameter: 6mm<br> Outer diameter: 20mm<br> Grit:150<br> Width: 5mm<br> Colour: As Shown<br> Material: electroplating emery<br> Package Contents:<br> 1 x Diamond grinding<br> Only the above package content, other products are not included.<br> Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.