A mold for forming an auger tip on a screw is disclosed. The mold has a pair of symmetrical secondary molds each has a base mold (50), a first mold (30) detachably received in the base mold (50) and a second mold (40) detachably received in the first mold (30) detachably received in the first mold (30) and having a forming edge (41) formed thereon so as to form the auger tip on the screw by colliding two forming edges together. Therefore, when the forming edge (41) is damaged and replacement thereof is necessary, a user is able to replace only the second mold to reduce the cost.