As well as inhouse x-ray and dye penetrant NDT facilities we use third party mechanical and magnetic particle testing to verify product conformity.
A wide range of ovens allows us to heat treat castings
and other components.
Standard tolerances, casting draft angles and shrinkage
allowances are detailed below:
Castings should be within linear tolerances of ±0.15 upto 150mm and ±0.05 upto 25mm thereafter.
SAND CASTING STANDARD TOLERANCES:
Castings should be within linear tolerances of ±1.0 upto 150mm and ±0.20
upto 25mm thereafter.
: The above tolerances are for guidance purposes only and may vary where contraction is hindered by design of the component / mould.
CASTING DRAFT ANGLES
: The draft or amount of taper given to the pattern to facilitate withdrawing from the mould depends somewhat on the size and shape of the pattern. A general guide would be 1 to 2 degrees of taper per side:
: Shrinkage allowances are approximate values only, since the exact allowance depends upon the size and shape of the casting and resistance of the mould. It is, therefore, possible that more than one shrinkage allowance will be required for different parts of the same pattern / casting. A general guide for aluminium alloy castings would be 1.3%.