INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING Vol. 10, No. 4, pp. 13-17 OCTOBER 2009 / 13 DOI 10.1007/s12541-009-0066-4 1. Introduction An endmill is a shank-type milling cutter, which is a cutting tool used in industrial milling applications. It is distinguished from the drill bit, in its application, geometry, and manufacture. Whereas a drill bit can only cut in the axial direction, a milling bit can cut in all directions, although some cannot cut axially. Endmills are used in milling applications, such as profile milling, tracer milling, face milling, and plunging. Different tool types and geometry may be used depending on the material being milled and the task being performed. For example, when milling a material such as aluminum, it may be advantageous to use a tool with a very shallow flute depth and a predulled (but polished) cutting edge. Endmills have traditionally been made from high-speed steel, but nowadays, they are mostly made of tungsten carbide, a rigid and wear-resistant material, and usually pressed from carbide powder into rods, which are then ground into blanks of industry-standard sizes. Endmills are typically made on computer numeric control (CNC) machines under a high-pressure lubricant, such as water, water-soluble oil, or a high-flashpoint oil. Grinding inside the machine is accomplished using abrasive wheels mounted on a spindle, and in some cases, multiple spindles. Depending on what material is being ground, these wheels are fabricated from industrial diamond (when grinding tungsten carbide), cubic boron nitride (when grinding cobalt steel), from another material (for example, when grinding ceramics), or set in a bond (sometimes copper). 1 Until recently, almost all endmill manufacturing was accomplished by grinding. This results in wasted material and also in a long processing time. The inefficiency of this process is compounded by the high cost of the grinding wheel. In endmill manufacturing particularly, the process of cutting the flutes for chip removal takes 30%–55% of the entire manufacturing time. If this grinding process is removed through manufacturing of pre-endmill blank using powder injection molding, then the manufacturing time and the loss of material can be greatly reduced. Figure 1 shows a comparison of conventional and PIM endmill manufacturing processes. Powder injection molding is a technique that combines general injection molding with sintering. Injection molding has mainly been used in manufacturing thermoplastics. However, much research has A Study of WC End-milling Manufacturing and Cutting Ability Evaluation by Using Powder Injection Molding Tae Jo Ko 1,# , Jong Han Kim 1 and In Joon Yoon 2 1 School of Mechanical Engineering, Yeungnam University, 214-1 Daedong, Gyeongsan, Kyoungbuk, Korea, 712-749 2 OSG Korea Co. Ltd., 354-48 Galsandong, Dalseogu, Daegu, Korea, 704-900 # Corresponding Author / E-mail: tjko@yu.ac.kr, TEL: +82-53-810-2576, FAX: +82-53-810-4627 KEYWORDS: Cutting Tool, Endmill, Grinding, Powder Injection Molding, Machinability The powder injection molding (PIM) technique is a manufacturing process that combines the versatility of plastic injection molding with the strength and integrity of machined, pressed, or otherwise manufactured small, complex, metal parts. When metal products are manufactured using injection molding, the process is both cost effective and time efficient. Nowadays, small metal products are manufactured using powder injection molding. Conventionally, cutting tools, such as endmills, are manufactured using a grinding process, because cutting tool materials are hard and have a high mechanical strength as well as a complex shape. To reduce the grinding time for the flute of an endmill, we suggested using an endmill blank method, where the flute is fabricated using PIM before edge grinding. This paper also describes how to finish the remainder of the cutting processes and discusses the performance of the formed cutting tool compared with a conventional tungsten carbide tool. Manuscript received: February 18, 2008 / Accepted: May 19, 2009 © KSPE and Springer 2009