Why investment casting
Where geometry rules out forging or sintering, investment casting delivers repeatable net-shape parts in heat-resistant and alloy steels at series volumes.
Components
- Turbocharger and exhaust components
- Rocker arms
- Shift and locking parts
- Brackets
Materials
Low-alloy steels, heat-resistant steels, stainless steels.
Frequently used alloys
| Grade | Type | Standard |
|---|---|---|
| 4140 | Cr-Mo quench-and-temper steel 42CrMo4 type | SAE J404 / AISI 4140 (cast: ASTM A732 Gr. 8Q) |
| 8620 | Ni-Cr-Mo case-hardening steel 21NiCrMo2 type | SAE J404 / AISI 8620 (cast: ASTM A732 Gr. 13Q) |
| HK | 25Cr-20Ni heat-resistant steel HK40 | ASTM A297/A297M |
| CF8 | Austenitic stainless steel, cast 304 type 304 type | ASTM A351/A351M, A743/A743M |
Typical requirements
High volumes, process capability evidence and cost pressure; investment casting competes where geometry rules out forging or sintering.
- Process capability evidence
- Sample submission before series
- Stable cost at volume
Related engineering topics
Process comparison
Qualitative comparison of investment casting with sand, shell mould, die, centrifugal and lost foam casting, forging, CNC machining, MIM, sheet metal, welding and additive manufacturing.
Design guidelines
Practical design-for-manufacture rules for investment castings: wall thickness, transitions, fillets, holes, cores, undercuts, ribs, bosses, draft, machining allowance and part consolidation.
Dimensional inspection
Dimensional inspection methods for castings: hand gauges, CMM, optical 3D scanning, form measurement, datum alignment, first article inspection and series control.