Casing of bit head

The utility model discloses a casing of a bit head, which is installed on a bit head rod of a rock drill and is used for drilling a blast hole on the rock. The utility model is composed of a powder removing groove on the upper part of a casing and a tail taper hole at the tail part of the casing and is characterized in that the top of the casing is an arch face, the upper part and the tail part of the casing are in circular arc transition connection, and the inner end face of the tail taper hole is a plane. When the utility model is machined into a bit head, grinding is not needed; the top of the casing is milled with a groove in which hard alloy is embedded and welded. The utility model has the advantages of good powder removing effect, high production efficiency and long service life.