Replaceable head drill body HYDRA with DIN 6535HE NC whistle notch shank, size 31/64" with an overall length of 105mm and flute length of 44mm according to DORMER standard for 3xD drilling with HYDRA P (R950), HYDRA M (R960) or HYDRA K (R970) diameter 0.4688 (15/32) up to 0.4844" (31/64)
For additional details please check the Manufacturer's site: