Darcast Crankshafts limited, Castings, Foundries, Engine Components, Automobile Components
Darcast English Version
Darcast German Version
Darcast Italian Version
Darcast Spanish Version
Darcast French Version

About Us | Process

Shell Moulding Process
Darcast has four state-of-the-art medium frequency electric melting furnaces capable of producing over 100,000 tonnes of base iron per annum. The Company converts the base iron produced in the electric melting furnaces into spheroidal graphite iron using the tundish method. Darcast utilises the shell-moulded process to manufacture its moulds. Given below are details of the historical roots of the shell-moulded process, the reasons why Darcast selected this technology as the most appropriate for crankshaft manufacture and the advantages the shell-moulded process offers to customers.
Overall, the shell-moulded process provides customers with the best quality crankshafts and the lowest total cost solution.

The History and Advantages of the Shell Mould Process

A Brief History

The shell-mould process was patented in Hamburg in 1944 by Dr Johannes Croning, and was originally referred to as the Croning process.

The shell-mould process offers the following advantages:
  • Near-net shape casting
  • Excellent casting surface finish and definition
  • Improved dimensional tolerances
  • Improved micro-structure of metal
  • Enhanced machinability


Shell Moulding

Darcast is in a unique position in its market of having complete control of its resin coated sand requirements as its parent company, Cornwall Holdings, owns the Yorkshire Mineral Company, the source and supply of its resin-coated sand.

The shell-mould process was chosen by Darcast as being the best process to manufacture cast crankshafts. Using the shell moulding process and Darcast's unique operational capabilities, it is possible to produce enhanced material specifications compared with other processes such as greensand manufacture.
Metal Micro-Structure
Typical metal micro-structure taken from a crankshaft produced using the greensand process
Metal Micro-Structure
Typical metal micro-structure taken from a Darcast crankshaft

Darcast uses a variety of methods for finishing crankshafts, ranging from hand finishing for complex and low volume items through to the use of automated finishing presses for high volume orders.