induration. 1. the process of hardening or being hardened.
1 They're weak against the Ice and Water types in reference of erosion, which cause this elements to the ground. 2  They're immune against the Electric type because in real life, the ground is a natural sink of electrons.  The Bug type resists them because many bugs like worms live inside the ground and many of them eat it.
Magneton Weakness. Steel is weak to Fire, Fighting, and Ground. they also cannot become poisoned and sleep will have a lower chance of success. Steel is weak to Joey's rattata. Actually, everything is weak to Joey's rattata.