The YG-1 EM639 TiAlN-coated carbide stub-length corner radius end mill has four flutes, a center-cutting design, and a 30-degree helix angle for high-performance machining of alloy steel, tool steel, mold steel, and other high-hardened materials up to Rockwell hardness C70. Corner radius end mills have a square end with rounded corners on the cutting edges to reduce chipping and extend the life of the tool. The stub length increases tool strength and makes it less likely to break in the material being machined. It is best used when depth of cut is shallow. Four flutes produce a better finish than fewer flutes. The center-cutting design has cutting teeth at the end of the tool, so it can be fed into the workpiece like a drill bit. The 30-degree helix angle balances lower angles€ strong cutting edge for difficult-to-machine materials with higher angles€ increased cutting action.

The TiAlN coating resists heat better than TiN and TiCN coatings, increasing tool life and performance. It also offers increased hardness compared to TiN and may reduce the need for lubricants based on the application. The high-performance carbide substrate provides better wear resistance and toughness than standard carbide. It is also harder than high-speed or cobalt steel, making it more wear resistant at high speeds and providing longer tool life. Cutting diameter tolerance is + 0.0000 to - 0.0012". The round shank accommodates a range of tool holders.

End mills are designed to remove material and create multi-dimensional shapes and profiles. They have cutting edges along the outside diameter and flutes that remove chips from the cutting area and allow cooling fluids to enter. If heat is not reduced effectively, the tool€s cutting edges will dull and additional material buildup can occur. The number of flutes can range from two to eight. Two-flute designs offer the most efficient chip removal, but more flutes provide a smoother finish. The shank is the end of the tool held in place by a tool holder or machine. Center-cutting end mills can create three-dimensional shapes and profiles, and make plunge cuts similar to a drill bit. Non-center-cutting end mills are for applications such as peripheral milling and finishing, but cannot make plunge cuts.

YG-1 manufactures drills, taps, end mills, and rotary tooling. The company, founded in 1981, is headquartered in South Korea and has a U.S. office in Vernon Hills, IL.