PERMANENT MOLD (Gravity Casting or Low Pressure Casting)
Molds are made of metal and coated with a die release. Molten metal is poured into the mold using gravity or very low pressure to fill the cavity. When solidified, the mold is opened and parts are ejected or removed by hand.
Available alloys: aluminum, zinc, copper-base alloys
Moderate dimensional accuracy, usually requires machining
Good surface finish, tight grain structure, pressure tightness
Moderate walls and generous draft required
Size range up to 35 lbs., equipment dependent
Tooling medium to high, volume and equipment dependent
Medium to high volume, equipment dependent
Moderate design restrictions, requiring sand or metal cores