The Pilot Mill is a specialized tool in the drilling industry used in milling operations within a well. Its primary function is to mill downhole tools and metal pieces that have fallen into the well or to create a new path for drilling. The tool has cutting teeth or diamond inserts at its lower part, which, by rotating and applying weight, can crush hard metals. The quality of the inserts and, especially, the method of applying them to the tool, is crucial and greatly affects the tool’s performance. Therefore, this process must be carried out under controlled conditions and supervised by a metallurgy specialist. Various sizes of Pilot Mills manufactured by Nasim Karvarzi Company are currently in use in the drilling industry.