The dewalt extreme bi-metal hole saw in 86mm handles larger-diameter penetrations for soil stacks, ventilation systems, and cable management through wood, metal, and plastic. A heavy-duty size for professional contractors working on commercial and residential building services. Features and benefits: patented tooth forms optimise chip removal for long tool life large continuous slot for fast, easy plug ejection hss cutting edge cuts wood, metal, and plastic deeper design cuts thick materials in one pass up to twice the lifetime of the previous generation