... 6V shape head66206Features Strong, durable, longer life than electroplated diamond toolGood For1. stone monument, tombstone, and so on ... Cutting, clearing bottom, drilling, 2D, 3D carvingMaterial applied for:Glass, ceramics, silicon slice, crystal, granite, marble, ... ) We have Professional laboratory for testing our Diamond Engraving Bit/Tools. Only when our Diamond Tools are Stable quality , ...