While cast irons can be welded, special techniques are required. Properties of the heat affected zones are greatly altered, to such an extent that it greatly compromises the iron's integrity. Welding should be considered only in cases of absolute necessity, such as when, for instance, repairs are needed.

On the other hand, because steel can be easily welded, this property can compensate for its poor castability because some defects are removable through proper welding operations without significantly altering the steel's properties.