Hertel E899921321 Square End Mill 1/4 in 4 Flute Hss Tin

Product Description

The HERTEL E899921321 is a double-end square end mill designed for milling operations in metal and general-purpose machining applications. Built from high speed steel (HSS) with a titanium nitride (TiN) coating, it offers improved wear resistance and surface hardness compared to uncoated HSS tooling. The mill measures 0.25 inches in diameter with a 0.375-inch length of cut and a 0.375-inch shank diameter, with an overall length of 2.875 inches. Four spiral flutes with a 30-degree helix angle promote efficient chip evacuation. This tool is intended for use by machinists and tool and die professionals in manual or CNC milling machines.

This end mill is suited for light-to-medium milling, slotting, and profiling operations on ferrous and non-ferrous materials in job shop, maintenance, and production environments. The double-end design extends tool life by providing two usable cutting ends. Right-hand cut and right-hand flute orientation are standard for conventional milling setups. The 30-degree helix angle balances cutting action and chip clearance across a range of materials. This tool is appropriate for use in knee mills, CNC machining centers, and similar equipment where a 0.375-inch collet or end mill holder is available.

Key Features

• Double-end design provides two cutting ends, extending usable tool life
• TiN coating improves wear resistance and reduces friction during cutting
• 4-flute spiral design with 30-degree helix for efficient chip evacuation
• Right-hand cut and right-hand flute orientation for standard milling setups
• High speed steel construction suitable for a broad range of machining applications
• Not center-cutting — not intended for direct plunge milling

Compatibility

Designed for use in milling machines and machining centers accepting a 0.375-inch shank end mill holder or collet. Suitable for general-purpose square-end milling operations where a 0.25-inch diameter tool is required.

Installation Notes

Installation should be performed by a qualified machinist. Ensure the machine spindle is fully stopped and locked out before changing tooling. Seat the shank fully and evenly in the collet or end mill holder and tighten to the tool holder manufacturer's specification. As this tool is not center-cutting, avoid direct axial plunge cuts — use ramping or helical entry strategies instead.