The Union Butterfield 963 uncoated cobalt steel square end mill has two flutes and a 30-degree helix angle for general-purpose machining on a range of materials. The two flutes have better chip-carrying capacity than end mills with more flutes while offering additional support when the tool goes into the material in applications with a high depth of cut. The cobalt steel substrate 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 broad range of materials. The tool’s square end creates sharp, unrounded cuts.
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. The center-cutting design has cutting teeth at the end of the tool, so it can fed into the workpiece like a drill bit; it can also be used for slotting and ramping. The cutting diameter tolerance is +0.003” to -0.000”. This tool has a Weldon shank that provides a secure hold in the toolholder and helps prevent slippage. It meets ANSI specification B94.19 for quality assurance.
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.