The YG-1 E2039 uncoated cobalt steel square nose end mill has four flutes, a center-cutting design, and a 30-degree helix angle for general-purpose machining and plunge milling on a range of materials. Four flutes produce a better finish than fewer flutes. The tool’s square end creates sharp, unrounded cuts. 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 for applications such as slotting, drilling, and profiling. The 30-degree helix angle supports general-purpose applications. It balances lower angles’ strong cutting edge for difficult-to-machine materials with higher angles’ increased cutting action.

Cobalt steel can be run at faster speeds and stays sharp longer than high-speed steel tools, while offering resistance to heat and abrasion. With no coating or surface treatment, this uncoated tool can be used on a range of materials. Cutting diameter tolerance is + 0.0010 to - 0.0000" for end mills with a different shank and cutting diameter and + 0.0015 to - 0.0000" for end mills with the same shank and cutting diameter. This tool has a Weldon shank.

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.