Drill bit and method of metallurgical and mechanical holding of cutters in a drill bit

A method of manufacturing a drill bit comprising the steps of:

• forming a drill bit head by a powder metallurgy utilizing a graphite mold having a series of proturbences for forming pockets, the proturbances having external dimensions slightly in excess of the inner dimensions of the finished pockets to allow for shrinkage during the furnacing of the drill bit head;
• and,
• attaching cutters having cutting faces into said pockets by:
• forming a plurality of substantially enclosed dimensionally controlled pockets in said drill bit;
• placing brazing foil in communication with the backs and bottoms of the cutters having excess foil protruding from above the top of the cutters;
• tap fitting the cutters and braze material into the cutter pockets;
• metallurgically attaching said cutters to said cutter pockets by heating said drill bit to a predetermined brazing temperature to expand the cutter pockets thus allowing the brazed foil to funnel into the pockets and substantially encompass said cutters;
• and
• shrink fitting said cutter pocket to said cutter by hydrogen cooling said drill bit.