Patent ID: 6926065

Claim:
A pressure responsive mold for casting a fishing sinker containing bismuth: a mold part having a fixed sidewall, said fixed sidewall defining a portion of an interior mold surface; a retractable member, said retractable member having a face for defining a further portion of an interior mold surface, said face and said fixed sidewall forming a cavity having a casting volume; an entry port for introducing a molten metal that expands during a solidification phase into the cavity in the mold; and a retaining member, said retaining member maintaining said interior mold surface and said face in position during an injection of a molten material therein, said retaining member retractable in response to an increase in the cavity pressure caused by solidification to displace the face relative to the sidewall to thereby form a solidification cavity wherein the face and the fixed sidewall contain a solidification volume that is greater than the casting volume.