Steel Types
Steel types shrug off most attacks which makes them a good defense for your team. There aren't many Pokemon that are of the Steel Types and even some that are of the Steel type lack substantial amounts of Speed(like Steelix). Steel types are all dual types except for Mawille and some can learn moves like Solarbeam and Focus Punch. Since Steel types are mostly dual types, they give a hard time for their opponent because the Steel type addition sometimes makes the opponent's moves only (1/4)x as effective.(Skarmory is in the Flying section)
Magneton is a Electic and Steel type that evolves from Magnemite. Magneton can learn moves like Thunder, Thunderbolt and Sonic Boom. It also can have the ability Sturdy that makes one-hit KO moves useless(moves like Sheer Cold). Magneton can be found in many places including New Mauville in Pokemon Ruby/Sapphire/Emerald and in the Power Plant in Pokemon LeafGreen/FireRed.