... LONGXIANG stone engraving bits include A, B, C, D, E , F , G series. Only appropriate Using stone engraving bits, to we could ... for using our bits and right parameters of engraving machine. D series: Whole alloy stone bits with three-arris made of ultra ... promote the rapid developmewnt of Chinese Diamond Tools industry. wholesale D 1 Straight Shank End Mill for Engraving Machine