Sand castings and shell moldings

ChinaTech Sourcing can source low cost, high quality sand castings and shell moldings from a selection of pre-approved ISO 9000 accredited factories in China. Rather than being restricted to just one or two suppliers, we are linked to dozens of established sand casting suppliers – enabling us to offer a wide range of manufacturing capabilities to meet your individual sand casting needs from manual low volume processes to fully automatic Disamatic moulding lines.

Sand casting and shell molding processes

The term sand casting (or sand molded casting) is used when a mold is formed from a sand mixture to produce a cast part. Molten liquid metal is poured into the mold’s cavity and then allowed to cool until the metal has solidified. Finally, the mold is broken away from the part to release the casting.

Shell molding (also known as shell-mold casting) uses a resin-covered sand to form the mold. In contrast to sand casting, this process offers greater dimensional accuracy, a higher productivity rate and is less labour intensive – making it ideal for small to medium parts requiring high precision.

Sourcing sand castings from China

All our castings are quality assured and supplied from factories with appropriate measurement equipment, such as laboratory testing, spectrometer, hardness / tensile testing, X-ray, microstructure testing, magnetic particle inspection (MPI) and dimensional measurement such as CMM machines. Stringent metallurgical control systems are in place to ensure that chemical and mechanical properties meet your exact requirements.

Although most foundries specialise in certain grades of material, as a sourcing agent we can supply most materials for both ferrous and non-ferrous sand castings to equivalent ISO Western grades, for example:

  • Ferrous sand castings -
    • Grey iron (BS EN 1561 Grades 150, 200 & 250)
    • Spheriodal graphite iron (BS EN 1563 Grades 400/15, 450/10, 500/7, 600/3 & 700/2)
    • In addition, we can offer austempered ductile iron
    • Steel (BS3100)
    • Carbon Steel (A1, A2, A3, A4, A5 & A6)
    • High tensile steel (BT1, BT2 & BT3)
    • Stainless steel (304 and 316)
  • Non-ferrous sand castings -
    • Aluminium (BS1490 Grades LM4, LM6, LM24, LM25 and LM27)
    • Copper based alloys - brass, phosphor bronze, gunmetal, aluminium bronze & manganese bronze
    • Zinc (ZA3 & ZA5)

The major saving gained by sourcing offshore parts is the labour and therefore labour-intensive secondary operations. As well as casting capabilities, our suppliers also have CNC machining and finishing facilities. It is always more economical to add maximum value to the component by sourcing castings as close to the finished part as possible. This also eliminates any potential issues on delivery with porosity or inclusions.

Quality

Prior to production supply all sand castings are initially supplied as PPAP (Production Part Approval Process) samples along with necessary ISIR (Initial Sample Inspection Reports) material composition and mechanical testing results. Ongoing production will be controlled with appropriate process documentation, control plans, gauging instructions and regular quality sampling via the inspection laboratories. Where necessary, SPC control can be applied to critical features. For your further peace of mind, all deliveries can be supplied with relevant chemical composition and mechanical test results.

Steel castings unfinished and machined, turned
Machined steel casting with plastic insert