Abstract: The invention provides a bit (10) for use with a rotatable tool, said bit including: a shaft (12) having a rearward end adapted to be held by a chuck of the rotatable tool, and a forward end (18) having cutting tips formed thereon; a reaming head (14) including a body having a bore (16) adapted to receive the shaft therethrough in a sliding fit, the body having a plurality of cutting blades (26) formed on at least one peripheral surface thereof; the bore and/or the shaft having formations thereon such that when the rearing head has the shaft operatively located in the bore the reaming head is rotationally locked into the shaft; the reaming head and the shaft being separable from each other to allow either component to be replaced independently of the other.