Cleveland C42051 Square End Mill 0.125 in 2 Flute Hss

Product Description

The CLEVELAND C42051 is a double-end, two-flute square end mill manufactured from high speed steel (HSS). It carries a 0.125-inch cutting diameter with a 0.375-inch length of cut and a 0.375-inch straight-cylindrical shank, also available with a Weldon flat. At 3.0625 inches overall length, this is a regular-length tool suited for general-purpose milling operations. The centercutting geometry allows plunge cutting as well as peripheral milling. Right-hand cut and right-hand flute direction follow the standard configuration expected by most vertical milling machines and CNC machining centers. Licensed machinists and toolroom technicians are the primary users of this tool.

The C42051 is designed for milling cast iron, non-ferrous metals, and steel. The 30-degree helix angle promotes efficient chip evacuation on these materials. The spiral flute design, combined with the centercutting tip, supports slotting, profiling, and light plunge operations. The regular length classification keeps deflection low during cuts, which is especially useful in close-tolerance work on small features where the 0.125-inch diameter would otherwise be prone to chatter or breakage.

Key Features

• Double-end design doubles tool life before replacement is required
• Centercutting geometry supports plunge milling without a pre-drilled pilot hole
• 30-degree helix angle promotes clean chip evacuation on steel, cast iron, and non-ferrous metals
• Straight-cylindrical shank with Weldon flat option for positive tool holding
• Uncoated HSS construction — resharpenable and compatible with standard HSS grinding wheels
• Regular length keeps tool rigidity high, reducing deflection on small-diameter cuts

Compatibility

Designed as an OEM-style replacement or direct-use cutting tool for standard ER collet chucks, Weldon-style side-lock holders, and set-screw end mill holders accepting a 0.375-inch shank diameter. Suitable for use in vertical milling machines, knee mills, and CNC machining centers. Primary workpiece materials are cast iron, non-ferrous metals, and steel as specified by the manufacturer.

Installation Notes

Installation is performed by a machinist or toolroom technician. Always power down the spindle and confirm zero rotation before changing tooling. Seat the shank fully into the holder and torque the retention screw or collet nut to the tool-holder manufacturer's specified value. Inspect the cutting edges for chips or wear before each use, particularly on a small-diameter tool like this where edge damage can lead to sudden breakage under load.