Now the part can be made to suit its function, without the need to compromise to meet manufacturing limitation. Draft angles and split lines are not required and problems in producing undercuts, helical forms and blind recesses can be largely ignored. All this becomes the pattern is made of an expendable material and the moulds are of a one piece construction, allowing complex shapes to formed in three dimensions. So investment castings reduce operations, simplify production control cut out sward and machining scrap, and as a result can often save capital costs on tools and equipment. In many instances they can replace multi-part assemblies with a lighter stronger component.
Complexity of shape means an investment casting is the next best thing to a finished component. Rough machining is eliminated and finishing operations are normally only needed working faces. Hence with the same machining set up you increase your productivity.
A far better quality finish is achievable than from most conventional casting processes. This varies according to alloys cast but for carbon steels is generally around 90 micro inches (1.5 Micro – Meters).
Extremely consistent tolerances can be held. As a general guide liner accuracy is to 0.005 in/inch (0.125 mm / 25 mm) but full tolerance details are given elsewhere.
If it can be melted then generally it can be investment cast. Such versatility results from the fact that the metal charge is melted in relatively small quantities and the hot ceramic mount into which it is poured is almost completely inert.
Tooling costs are relatively low for investment castings and machined dies will have an almost indefinite life. Once dies exist relatively small quantities can be made at economical prices. Depending upon work-load lead times for repeat orders can be quite short 6 – 8 weeks being a fairly average delivery period.