The Union Butterfield 9009 uncoated cobalt steel square end mill has a multi-flute design, a 30-degree helix angle, a long-length design, and coarse-pitch, chip-breaking cutting edges for roughing applications that require a longer reach than standard-length end mills. The number of flutes varies; fewer flutes provide better chip-carrying capacity, while more flutes produce a finer finish. Roughing end mills are special-purpose tools whose chip-breaking cutting edges create small chips for heavy cuts and remove more material in less time than conventional end mills, with minimal vibration (chatter). The coarse-pitch tooth design allows the end mill to be used to cut softer, gummier materials. The end mill produces a rough finish that can be smoothed by a second finishing cut. The long-length design has longer cutting edges than standard-length end mills for deep slotting and 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, as well as roughing 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 be fed into the workpiece like a drill bit; it can also be used for slotting and ramping. The cutting diameter tolerance is +0.005” to -0.000”. This tool has a Weldon shank that provides a secure hold in the toolholder and helps prevent slippage. This tool 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.