Are you thinking of these spells?
Ironguard, Lesser (SC, FRCS)
Abjuration
Level: Sor/Wiz 5
Components: V, S, M
Casting Time: 1 standard action
Range: Touch
Target: Creature touched
Duration: 1 round/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
You watch as your target's skin lightens and takes on a translucent look.
The subject of lesser ironguard becomes immune to nonmagical metal. Metal items (including metal weapons) simply pass through you, and you can walk through metal barriers such as iron bars. Magic metal affects you normally, as do spells, spell-like abilities, and supernatural effects. Attacks delivered by metal items (such as poison on a dagger) affect you normally. If the spell expires while metal is inside you, the metal object is shunted out of your body (or you away from the metal, if it is an immovable object such as a set of iron bars). You and the object each take 1d6 points of damage as a result (ignoring the object's hardness for determining damage to it).
Because you pass through metal, you may ignor armor bonuses from metal armor on opponents you attack with unarmed attacks.
Material Component: A tiny shield of wood, glass, or crystal.
Ironguard (SC, PGtF)
Abjuration
Level: Sor/Wiz 7
Components: V, S, M, F
This spell functios like lesser ironguard, except that the subject you touch is immune to magic metal as well.
Material Component: A tiny shield of wood, glass, or crystal.
Focus: A small nugget of adamantine worth 100 gp.