A U-shaped bolt including a closed end and two legs at an open end is self-retaining on a first object. The U-shaped bolt includes projections forming an opening to the closed end adapted to be smaller than the width of the first object. The projections retain the U-shaped bolts on the first object. The U-shaped bolt is used in conjunction with a space heater having a plurality of heating elements connected by channels. The U-shaped bolt is retained on the channels to warrant proper assembly of the space heater.