History of the Investment / Lost Wax Casting Process
Investment Casting using the lost wax technique is not new, on the contrary , it is one of the oldest casting methods known and examples of its use to produce statuary and jewelry can be traced back to antiquity. In the early part of this century the method was applied to the manufacture of gold fillings and dental inlays for false teeth, while in 1932 the lost wax ceramic block mould process was developed, using cobalt-chromium alloys for dental applications, and orthopedic components. The demands of the second world war changed the limited application of the technique and in the wake of the introduction of the aircraft gas turbine and intensified development of turbo chargers for high flying bombers and fighters, designers were drawn to investment casting to produce the necessary high quality components.

The 1950's saw the expansion of the industry, mainly allied to aircraft and military applications but with a significantly increasing involvement in the general commercial field. With the introduction, in the mid of 50's of the ceramic shell mould process, the range of materials cast increased dramatically and to the original alloy steel and super alloys were added carbon steels, tool steels, aluminum alloys, copper alloys, magnesium alloys, and more recently, titanium alloys, typifying the versatility of the process.
Why Investment Casting?

With it's numerous advantages, Investment Casting finds it's application in various industries as:
a.
Design Flexibility
Investment casting produces near-net-shape configurations, offering designers and engineers freedom to design the part of maximum function The process is capable of producing precise details like complex undercuts, slots, holes, lettering and dimensional accuracy in parts weighing many pounds or just few ounces
b.
Reduce production cost
Investment casting offers a combination of features which can translate to cost saving benefits for you. The piece price for investment casting is not always the lowest, but the saving is reduced machining, material costs, and tooling start-up costs make the lost wax process very competitive when you consider overall cost.
c.
Wide choice of alloys
Even alloys that cannot be cast by other methods or which are difficult to machine can be investment cast, more than 100 ferrous & non ferrous metals are routinely cast.
d.
Close tolerance
Investment casting promises tight linear tolerances of an average +_ 0.15mm/ inch, with even more exact tolerances depending on the part size & complexity.
f.
Tooling Economy
Our tooling is usually much less expensive than tooling for other "hot" methods, since dies are built to withstand wax injection rather than metal injection.
g.
Weight Reduction
Investment casting process can eliminate unnecessary metal and weight from non functional areas of the part.
General Tolerances
Flatness
Length(mm)
Tolerance TIR
Upto 25.0
0.2
Over 25.0 to 50.0
0.4
Over 50.0 to 75.0
0.6
Over 75.0 to 100.0
0.8
Over 100.0 to 125.0
1.0
Ovality Tolerances
Diameter (mm)
Tolerance TIR
Upto 25.0
0.24
Over 25.0 to 75.0
0.48
Over 50.0 to 75.0
0.72
Over 75.0 to 100.0
0.96
Over 100.0 to 125.0
1.20
Linear Tolerances
Linear (mm)
Tolerance TIR
Upto 25.0
0.12
Over 25.0 to 50.0
0.24
Over 50.0 to 75.0
0.36
Over 75.0 to 100.0
0.48