Sgs 39139 Square End Mill 5/16 Inch 4 Flute Solid Carbide

Product Description

The SGS 39139 is a solid carbide square end mill designed for precision metal removal in machining centers and CNC milling operations. It features a 5/16 inch cutting diameter, a 13/16 inch length of cut, and a 2-1/2 inch overall length. Manufactured from micrograin solid carbide, the 39139 carries a TiN finish and a 30-degree helix angle with a variable index design that helps reduce harmonic vibration during cutting. Four spiral flutes and a center-cutting geometry allow both plunge and peripheral milling. This tool is intended for use by machinists and toolroom professionals in production and job-shop environments.

The SGS 39139 is suited for milling a broad range of workpiece materials, including hardened steels, cast irons, stainless steels, non-ferrous metals, structural steels, and high-temperature alloys, corresponding to material codes H, K, M, N, P, and S. Its straight-cylindrical shank fits standard ER collets, end mill holders, and shrink-fit tooling at the 5/16 inch shank diameter. The regular-length profile makes it a practical choice for slotting, profiling, and contouring operations where tool overhang must be minimized to maintain rigidity and surface finish quality.

Key Features

• Micrograin solid carbide construction for wear resistance and edge retention in demanding materials
• TiN finish reduces friction and extends tool life across multi-material applications
• Variable index flute spacing reduces chatter and harmonic vibration during cutting
• Center-cutting geometry allows direct plunge entry without a pre-drilled pilot hole
• 30-degree helix angle promotes efficient chip evacuation in spiral flute configuration
• Right-hand cut, right-hand flute with straight-cylindrical shank for broad toolholder compatibility

Compatibility

Compatible with workpiece material codes H, K, M, N, P, and S as specified by the manufacturer. The 5/16 inch straight-cylindrical shank seats in standard ER collet chucks, side-lock holders, and shrink-fit holders designed for that shank diameter.

Installation Notes

Installation should be performed by a qualified machinist following the toolholder manufacturer's clamping torque and runout specifications. Verify spindle and toolholder runout with a dial indicator before engaging the cut, as excess runout accelerates edge wear and can cause tool failure. Always bring the spindle to a full stop before measuring, adjusting, or removing tooling. Follow your machine tool builder's guidelines and applicable shop safety procedures when handling carbide cutting tools.