Shell Molding
Shell molding, also known as pre-coated sand casting, forms a thin, rigid mold shell by blowing resin-coated sand onto a preheated metal pattern, where the heat cures it into a shell or sand core of a certain thickness. The shell halves and cores are then assembled in a flask and filled with molten metal. At the heart of the process is the pre-coated sand itself, a blend of silica sand, thermoplastic phenolic resin, hardener, and lubricant. Its excellent flowability makes it especially good at forming complex cores.
Sand Shell
Pouring Line
Connector
The shell molding process can be used for the production of cast steel and cast iron parts. With broad application, high efficiency, and better surface quality than ordinary sand casting, it is a widely used process in production.
- Cast Iron: Gray Iron (e.g., HT150, HT200)
Ductile Iron (e.g., QT400-15, QT500-7) - Cast Steel: Carbon Steel (e.g., 45#, WCB) Various Alloy Steel Grades
- Stainless Steel: 304/304L, 316/316L, 17-4PH, and other commonly used stainless steel grades
- Aluminum Alloys: ZL101, ZL111, etc. cast aluminum alloys
- Copper Alloys: Tin bronze, Aluminum bronze
| Part Weight | 0.2 kg - 50 kg |
| Dimensional Accuracy | CT9 - CT10 |
| Surface Roughness | Ra 3.2-6.3 μm |
| Wall Thickness | 5-15 mm |
- Raw and auxiliary materials →
- pre-coated sand preparation →
- sand shooting and molding/core making →
- heat curing →
- pattern removal and dressing →
- core assembly and mold closing →
- melting and pouring →
- cooling →
- shakeout and cleaning →
- final inspection
A key characteristic of shell molding is that it is better suited to thinner-walled parts, typically 5 to 15 mm. Paired with automated molding lines such as DISA and Hunter, it produces large volumes of castings efficiently, making it ideal for high-volume production.
- More than 30 years of manufacturing and export experience, with extensive knowledge of international logistics and industry-specific technical standards.
- Full support from tooling design and sample development through to high-volume production, precision machining, and surface treatment.
- A strict ISO 9001 quality management system, backed by CMM (coordinate measuring machine) inspection and non-destructive testing (MT, RT, PT).
