Commercial Grade Investment Casting
Commercial grade investment casting is a relatively new process in the UK and offers some distinct advantages over sand casting: the surface finish and cast tolerances are similar to sand casting but it also offers many benefits of the premium grade investment casting such as design flexibility, good cast integrity and the ability to produce parts without draft angle consideration.
The commercial grade investment casting process has many similarities to premium grade investment casting but is best suited to larger, less complex designed parts that may require a higher level of repeatable quality and integrity than general sand castings.
- Piece price significantly lower than premium grade investment casting
- Cast surface is smoother than sand casting
- More design flexibility (complex shapes)
- No draft angles required
- The cast tolerances are wider
- Consistency and repeatability: virtually no tool wear
- Precision: details such as holes, lettering, threads, serrations can be cast
- Production flexibility: accommodating both high and low volume
- Reduced production costs: minimal material wastage, machining can often be eliminated and labour costs reduced
- Low initial tooling costs
- Added value: ability to incorporate company name, logo, part number etc.
Commercial grade investment casting offers most of the advantages of premium grade investment castings at a reduced piece price with higher level of repeatable quality and integrity than general sand castings.
The process is capable and our services include to the following:
- Cast surface roughness typically 25.4Ra
- Machined surface roughness: 1.6-3.2Ra
- Weight capabilities: 0.01kg to 100kg
- Size capabilities: 100mm to 1500mm
- General cast tolerances: ISO 8062 CT range CT8-CT9
- ISO 9001, TS16949 approvals
- Materials include carbon steel and some stainless steel alloys
- Consistent lead times with stockholding options
- A wide range of finish options including painting, polishing, plating, anodizing and more.
- Heat treatment, machining, assembly options
- 3D design support with digital casting simulations
- Rapid prototyping prior to production
- Medium to large volume runs
- Wide market applications: oil & gas, automotive, aerospace, rail and more.
Commercial grade investment casting is a very similar manufacturing process to premium grade investment casting or lost wax process where the differences between the processes facilitate lower costs of supply:
- An aluminium tool is cut directly from the 3D CAD data
- Wax replicas are produced from the tooling
- Waxes assembled onto runner system – “tree”
- A ceramic shell is built around the assembly using an automated, high speed dipping and drying process (investment)
- The wax is then removed from the shell in water
- The shell is fired in an oven
- The molten metal is poured into the shell
- Ceramic is broken off once the metal has cooled
- Parts are cut off the “tree”
- Ingate (feed positions) are ground off
- Finishing and machining if required
- Necessary inspection