Gravity

Castings are produced by pouring molten metal into permanent metal moulds. (Generally made from Cast Iron). This process produces 'Chill Castings'.

Advantages
  • Lower set up cost than Pressure Diecasting
  • Higher casting rate than sand casting
  • Low gas porosity levels are possible
  • Fine grain sizes may be obtained
  • The highest quality castings with regards to mechanical integrity can be produced by this method
  • Less finishing is required than for sand castings
Limitations
  • Minimum wall thickness 3-5mm
  • Linear tolerance is approximately 3mm/m
  • Surface finish better than sand casting
  • The complexity of possible casting shapes is limited
  • Casting weight range 0.1Kg - 70Kg
  • Approximate economical quantity range 500 - 2500 (This may increase where sand cores are used to produce shapes impossible with pressure diecasting)