Robbjack S1-401-03 Square End Mill 3/32 in 4 Flute Carbide

Product Description

The ROBBJACK S1-401-03 is a solid carbide square end mill designed for precision milling in metalworking and machining applications. Built to Series S1-401 standards, it features a 3/32 inch (0.0938 inch) cutting diameter, a 3/16 inch length of cut, and a 1/8 inch straight-cylindrical shank. The four-flute, right-hand spiral design with a 30-degree helix angle promotes efficient chip evacuation and smooth cutting action. At stub length with a 1-1/2 inch overall length, this end mill offers added rigidity for tight-tolerance work. It is centercutting capable, allowing direct plunge entry into workpiece material. Machinists and CNC operators install this tool in milling machines and machining centers for finishing and light slotting operations.

This end mill is suited for small-feature milling in ferrous and non-ferrous materials where a compact, rigid tool is required. The stub length profile minimizes deflection during high-precision passes. The uncoated solid carbide construction at C2 material grade makes it appropriate for use in aluminum, brass, mild steel, and similar materials. It is commonly used in job shops, tool rooms, and production CNC environments where accurate small-diameter milling is required.

Key Features

• Solid carbide construction, C2 material grade for rigidity and wear resistance
• Four flutes with right-hand cut and right-hand spiral flute direction
• 30-degree helix angle for efficient chip evacuation
• Centercutting design allows direct plunge milling
• Stub length (1-1/2 inch OAL) provides added rigidity and reduced deflection
• Uncoated finish suitable for a range of common workpiece materials
• Straight-cylindrical shank for standard collet or end mill holder compatibility

Compatibility

Designed as an OEM-style replacement or standard tooling option for milling machines and CNC machining centers accepting a 1/8 inch straight-cylindrical shank end mill.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator. Ensure the machine spindle is fully stopped and locked out before changing tooling. Seat the shank fully in a clean, properly sized collet or end mill holder and torque the retention mechanism per the holder manufacturer's specification. Verify runout with a dial indicator before beginning cuts to confirm proper seating.