A shaft bottom (20) with a sole plate (2) and a casing (3) has a channel connecting an inlet opening (5) with an outlet opening (6). The channel (9) is formed of a cavity (21) which broadens conically towards the top and is arranged concentrically to the axis (11) of the shaft bottom (20), and of two slit-like recesses (22) which lead radially outwards from the cavity (21) to the inlet opening (5) and outlet opening (6). For the production of such shaft bottoms (20), a mould is proposed which has a substantially cylindrical casing (132) and a mould core (131). The mould core (131) has a truncated cone shaped section (134) which tapers to the top in the position of use, the top end (133) of which is hemispherical. In order to form the channel (9) in the shaft bottom (20), two channel moulded pieces (135) are arranged on the mould core (131). The channel moulded pieces (135) have sleeve-shaped inserts (119).