What is the primary advantage of using chipbreakers in metal cutting?

The primary advantage of using chipbreakers in metal cutting is to manage chip size and form. Chipbreakers are geometric features incorporated into the cutting tool that control the way material is removed from the workpiece. When machining metals, the cutting operation generates chips that can be long, continuous, and unmanageable, which can hinder the machining process and cause damage to the tool or workpiece.

By using chipbreakers, the cutting process is optimized as they effectively break the chips into smaller, manageable pieces. This not only improves the efficiency of the machining operation by preventing chip entanglement but also enhances the overall safety and cleanliness of the workspace. Proper chip size and form reduce the risk of chips causing scratches on the workpiece or interfering with the cutting tool's performance.

While extending tool life, decreasing cutting speed, and improving material feed rate are important factors in metal cutting operations, the specific role of chipbreakers is to primarily control chip characteristics, making option B the most appropriate answer.