What it does: Heavy-duty high-speed steel bridge reamers,expand or align existing holes through mild steel, alloys, aluminum, wood, plastic, fiberglass, or any material of similar hardness prior to rivet or bolt installation, Deburring and trimming of holes in structural materials. Application: Especially for steel, metal, alloy aluminum, brass, plastic, iron, nickel, copper, cast iron and other structural materials. Design: Tapered point design allows reamer bits to enter irregular overlapping holes, aligning bolt holes. Note: The 1Inch Bridge Reamer Bit is not a drill bit, only aligns the reamer with the pre-drilled hole. If you need to enlarge the hole to 1Inch. Must have a pre-drilled first, then reamed to 1inch. Material: Made of high-quality steel, high toughness, high temperature resistance, corrosion resistance, long service life. Applies to:The reamer bit fits for Steel Metal Wood Alloy to Align Existing Hole and Enlarge Hole Function: Align existing holes and enlarge