Diamond Grinding Cups Manufacturer & Supplier, from Liaocheng Jinquan Construction Machinery Co.,Ltd, China. Available with a choice of Hemispherical, Ballistic Semi Ballistic, Paraboloid or Conical pins, in sizes 6mm to 25mm. Other sizes are available on request. Atlas Button Bits Diamond Grinding Pins: - specially formulated matrix for maximum performance - maintain proper profile time and time again - Strategically positioned flushing outlets for improved flushing and cooling - maximize drilling economy - field proven Normal Models: Diaroc/King pin (Shank=8mm); Diamond grinding pin (Shank=9mm); Pin-Atlas model pin; Internal Hex model pin.