Investment (Lost Wax) Casting Process

Casting Process Comparison Chart

Process Investment
(Lost Wax)
Green Sand Dry Sand
(Chemical or Vapor Cure)
Permanent Mold
(Gravity Die Casting)
Die Casting
Metals Cast Nearly all ferrous and non-ferrous alloys Wide range of ferrous and non-ferrous alloys Wide range of ferrous and non-ferrous alloys Nonferrous alloys (Al, Zn, Mg, certain Cu), some Fe Nonferrous alloys only (Al, Zn, Cu, Mg, Sn, Pb)
Complexity of Shape 4 (Greatest) 3 3 2 1 (Least)
Casting Weight Ounces to 250 lbs. Ounces to Tons Ounces to Tons Ounces to 250 lbs. Ounces to 40 lbs.
Min. Section Thickness 0.020″-0.080″ 0.125″-0.250″ 0.060″-0.250″ 0.060″-0.250″ 0.025″-0.080″
Linear Dimensional Tolerances Under 1″: +/-0.005″. Over 1″ add +/- 0.003 in.in +/- 0.015-0.250 in Add +/- 0.015″-0.250″ across parting plane +/-0.020-0.060 in. Add +/- 0.020″-0.060″ across parting plane Under 1″: +/- 0.010. Over 1″ add +/- 0.002 in/in. Add +/-0.015-0.060″ across parting plane +/-0.0015-0.005 in Add +/-0.001″-0.005″ across parting plane
Surface Finish (Micro Inches) 63-125 150-500 150-250 150-350 32-63
Tooling Costs Low-to-Moderate Low Low Moderate High
Optimum Lot Size Small-to-Medium depending on degree of process mechanization Small-to-large depending on degree of process mechanization Small-to-medium depending on degree of process mechanization Medium Large
Draft Required None 1-5 degrees 1-3 degrees 2-5 degrees 1/2 to 2 degrees
Advantages No Parting Plane. Accommodates nearly all metals. Near-net-shape castings require minimal machining. High production rates possible through mechanization Moisture-free mold Mold life of 15,000 cycles or more depending upon pouring temperature of metal and upon casting specs. Both metal and sand cores are used. Mold life from 15,000 cycles depending upon pouring temperature of metal and upon casting specs. Near-net-shape castings require minimal machining.
Disadvantages Mold is not reusable. Mold materials not reusable. Process is labor and energy intensive Mold is not reusable. Mold is not reusable. Some shapes cannot be cast. Sealing may be required to achieve pressure or leak tight castings. Metal cores only. Sand cores cannot be used.