Plaster Mould Casting

Permeable plaster moulds give a smooth surface finish (80~125 rms) with a finer surface detail than is obtainable with shell moulds. Castings as thin as 0.5mm are possible. Slow solidification rates reduce internal stresses so that any casting distortion is negligible.

Machining and finishing operations may be eliminated by the use of plaster moulds. Small holes may be cast to size ready for tapping. Surface finish and dimensional accuracy equates to die casting qualities. LM25 alloys are commonly cast by this process.