Furnace for the heat treatment of drills

In a furnace having a heat area and a quenching area for a partial heat treatment of drills and other tools having a clamping portion and a working portion in which different properties, particularly hardness, are to be imparted by a heat treatment solely to the working portion, the improvement comprising

• a tool receiving member movable in said furnace from said heating area to said quenching area, said tool receiving member including means for holding a plurality of said tools such that the working portion of the tools is freely exposed to the heating and quenching as said tool receiving member moves from said heating area to said quenching area, and means for maintaining the clamping portion of said tools at substantially the same temperature level during the heating and quenching,
• said tool receiving member comprises a plate-like support member including a plurality of recesses of predetermined size to engage with the respective clamping portions of said tools such that the working portion of said tools projects away from said support member,
• means for cooling said support member to maintain said clamping portions at said temperature level during the heating,
• the heating area has a hearth engageable with said support member and said hearth includes said means for cooling said support member, and
• means for furnishing relative movement between said hearth and said support member to bring said hearth and said support member into contact with each other and to space said hearth respectively and said support member from each other.