Accupro 39451 Square End Mill 1 in 4 Flute Powdered Metal

Product Description

The ACCUPRO 39451 is a 1-inch diameter square end mill designed for general-purpose milling operations in ferrous and non-ferrous metals. It features 4 spiral flutes, a 2-inch length of cut, and a 1-inch shank diameter, with an overall length of 4.5 inches. Constructed from powdered metal, it delivers consistent hardness and wear resistance compared to standard high-speed steel. The uncoated finish suits shops that re-sharpen tooling or prefer uncoated substrates for specific materials. This is a centercutting tool, meaning it can plunge directly into the workpiece. Machinists and tool-and-die professionals install this type of end mill in CNC machining centers, knee mills, and manual vertical mills.

The 39451 is suited for peripheral milling, slotting, and plunge cutting in production and job-shop environments. Its right-hand cut and right-hand spiral flute configuration is the standard orientation for conventional vertical milling setups. The 2-inch length of cut allows work in moderate-depth pockets and slots. No chipbreaker geometry is present, making this a smooth-flute tool appropriate for finishing passes or applications where chip geometry is managed through feed and speed selection rather than tool geometry.

Key Features

• 1-inch cutting diameter with a mill diameter tolerance of +0.003 / -0.000 inches
• Powdered metal construction for uniform hardness and extended tool life vs. standard HSS
• 4 spiral flutes with right-hand cut and right-hand flute direction
• Centercutting design allows direct plunge entry into the workpiece
• 2-inch length of cut for moderate pocket and slot depth
• Uncoated finish — compatible with re-sharpening and select material applications

Compatibility

Designed as a standard single-end square end mill with a 1-inch straight shank, compatible with ER or end-mill-style collet holders and shell mill adapters accepting a 1-inch bore.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer's toolholding specifications. Ensure the spindle is fully stopped and locked before loading or removing the end mill. Seat the shank fully into the collet or holder to the minimum engagement depth recommended for the holder type. Verify runout with a dial indicator before beginning the cut, as excessive runout accelerates edge wear and degrades surface finish.