FREEFORM BELL HANGERS These Bell Hangers have a high speed steel, aggressive fast spiral design and a wire pull hole at the chuck end. The 1/4" shaft is great on shorter lengths for strength when drilling through headers. Made with "metal cutting" grade high speed steel, this bit is not to be confused with softer(high carbon steel) bits with a hole. The tooling required to put a hole in this particular grade of steel is a complex, labor intensive process.
The WH Series is the 2 Hole Series that has a 118° split point, slow spiral, high speed steel bit tip for additional strength.