The Snap-On BAHCO 3830-102-VIP 4-Inch bi-metal holesaw is equivalent to 102 millimeters in metric measurement. It Combines a flexible shatter resistant spring steel back with a high speed steel cutting edge to provide faster, more durable cutting power. The cutting edge features 4 to 6 teeth per-Inch and is an electron beam-welded to a tough alloy back and then the teeth are precision ground to further increase cutting efficiency. This holesaw cuts clean, accurate holes in virtually any machinable material. The vertical slots allow for easy core removal.