(57) An inductive heating apparatus comprising an induction furnace (1) and induction heating coil (10) embedded within a refractory block (6) of cylindrical form and a metal susceptor sleeve (7) arranged with a clearance in the bore of the refractory block (6). The susceptor sleeve extends below the bottom of the refractory block (6) and is supported in a metal support collar (8). A cylindrical canister (4) is positioned inside the refractory block (6) and is supported on a movable lower refractory pressure pad (3) located on top of a water cooled hydraulic ram (5). An upper refractory pressure pad (2) is provided above the cylindrical canister (6) and serves as an abutment means when the lower refractory pressure pad (3) and cylindrical canister (4) thereon are moved upward. The induction heating coil (10) may also have a number of tappings (A, B, C) for progressively increasing the length of the heating zone.