Kennametal 1280478 Indexable Thread Mill 0.39 in

Product Description

The KENNAMETAL 1280478 is an indexable thread mill designed for cutting both internal and external threads in metalworking applications. The tool accepts a single STN11-style insert held in place by a screw-clamp method, providing consistent thread form repeatability across production runs. With a cutting diameter of 0.39 inches and an overall length of 3.12 inches, it fits into compact machining envelopes while maintaining rigidity through its 0.29-inch neck diameter. Through-coolant capability directs fluid directly to the cutting zone, supporting chip evacuation and tool life in ferrous and non-ferrous materials. This tool is used by machinists and CNC operators in job shop and production environments.

The 1280478 is suited for threading operations on machining centers and CNC mills where a single-point or tap approach is impractical. Its 0.61-inch maximum hole depth supports shallow-to-moderate thread lengths on internal bores, while the external threading capability extends its use to stud and boss features. The K039 toolholder style and 1/4-inch insert inscribed circle are key selection parameters when matching this body to available insert inventory. One threading insert is required per setup.

Key Features

• Cuts both internal and external thread forms with a single tool body
• Through-coolant design improves chip flushing and reduces heat at the cutting edge
• Screw-clamp insert retention with STN11 insert style for secure, repeatable seating
• 0.29-inch neck diameter provides clearance in tight-bore entry conditions
• Single-flute design simplifies programming and reduces cutting forces
• 3.12-inch overall length accommodates standard toolholder stick-out requirements

Compatibility

Designed for use with STN11-style threading inserts with a 1/4-inch inscribed circle, mounted in a K039-style toolholder. Specific insert compatibility should be confirmed against KENNAMETAL insert selection charts for the 1280478 body.

Installation Notes

Installation and operation of this tool should be performed by a qualified machinist or CNC programmer familiar with thread milling cycles. Ensure the machine spindle is fully stopped and the tool is securely clamped in the holder before handling or insert changes. Verify through-coolant passages are clear and coolant pressure is within the machine tool specification before running the program. Follow the toolholder manufacturer torque guidelines when seating the clamping screw to avoid insert damage.