[Taqwus]

Elfbane, Control, and Smasher also come to mind. Weapons of Sharpness is another way to get mass armor-piercing weapons. There are also armor-negating non-elemental attack forms (that Golem is probably wearing Elemental Armor, right?) such as Abomination's Gaze o' Death (area 5, 15-pt an+mr).
Smacking a Golem few times with Gate Cleaver should also suffice, and if it's the only mage controlling the Mechanical Men that's that for them as well.