Robbjack S1-301-12 Square End Mill 3/8 in 3 Flute Carbide

Product Description

The ROBBJACK S1-301-12 is a solid carbide square end mill designed for precision milling in metalworking and machining applications. Built to Series S1-301 standards, it features a 3/8 inch cutting diameter, a 5/8 inch length of cut, and a straight cylindrical shank at 3/8 inch diameter with a 2-1/2 inch overall length. The three-flute spiral geometry with a 30-degree helix angle promotes efficient chip evacuation and smooth cutting action. This is a stub-length, uncoated, centercutting tool suited for general-purpose slot milling, peripheral milling, and plunge cutting on machining centers and manual mills.

This end mill is used in job shops, production machining environments, and toolrooms where consistent dimensional accuracy is required. Its stub length reduces overhang and improves rigidity, making it well-suited for short-reach milling operations in ferrous and non-ferrous materials. The right-hand cut and right-hand flute configuration matches standard spindle rotation on most vertical machining centers and CNC mills. Machinists, toolmakers, and CNC operators working with C2-grade carbide tooling will find this a direct fit for general milling work.

Key Features

• Solid carbide construction, C2 material grade, for hardness and wear resistance
• 3-flute spiral design with 30-degree helix angle for efficient chip removal
• Centercutting geometry allows direct plunge entry into workpiece material
• Stub length profile reduces overhang for improved rigidity and reduced deflection
• Uncoated finish suitable for use with cutting fluids on a wide range of materials
• Right-hand cut, right-hand flute orientation compatible with standard CNC spindles

Compatibility

Designed as an OEM-style replacement or direct tooling selection for standard 3/8 inch straight-shank tool holders, collets, and end mill adapters on vertical machining centers and manual milling machines.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator. Ensure the spindle is fully stopped and the machine is powered down before changing tooling. Use a properly sized collet or end mill holder to secure the straight cylindrical shank, and verify runout with a dial indicator before beginning a cut. Follow shop safety procedures and applicable OSHA machining guidelines when handling carbide cutting tools.