Florence recognized four types of integration between these metal industries:(i)vertical integration (e.g. links between the refining of non-ferrous metals and the production of non-ferrous hardware products); (ii) convergent Integration (e.g. the manufacture of bolts, car bodies, tyres, etc., feeding oonvergently into the motor assembly industry); (ib) diagonal integration (e.g. foundries and tool manufacturers serving a number of local industries); and (iv) indirect integration (e.g. food industries which, with their strong preponderance of female workers, tended to balance the preponderance of male employment in the metal industries).