100 Metal Arrow in ARK: Survival Evolved are advanced arrows fired only by the Compound Bow that can pierce armor. Heavy, hence cannot be used in a Bow or Crossbow.

Notes
Like other arrows and Spear Bolts, an unbroken Metal Arrow can be retrieved from surfaces, corpse or unconscious creature where it is attached.
Does more damage than Longneck Rifle(with Simple Rifle Ammo) and Fabricated Sniper Rifle if fully charged.
Metal arrows can be used to full effect against the Rubble Golem, making it useful for cave runs on Scorched Earth.
Metal arrows do not pierce through regular Rock Elemental, as they suffer the same 90% damage reduction as most physical attacks.
Surprisingly useful in PVP, as it pierce through armor that high-end players usually rely on to survive and head shots can be instantly lethal.