Reamer Tek Wood to Steel screws are White Zinc Coated. For specialized applications specifically fastening wood to steel or aluminum. They have an advanced design that makes even the hardest jobs accomplished in less time, less money and less fatigue! Self-drilling wings will break off once they reach contact with steel or Aluminum. Milled with heat treated hardened steel! Ideal For Truck beds, Trailer decks / beds, Horse trailers, Snowmobile trailers, 4wheeler trailers and more!