Kennametal 3331090 Indexable Boring Bar 0.44 in Right Hand

Product Description

The KENNAMETAL 3331090 is a heavy metal indexable boring bar designed for precision internal turning operations on CNC lathes and boring machines. Built to the L-MNE toolholder style under the Top Notch series, it features a right-hand cut orientation and accepts N.1L inserts secured by a clamp-style holding method. The shank diameter is 5/16 inches, minimum bore diameter is 0.44 inches, and overall length (OAL) is 6 inches. The center-to-cutting-edge dimension is 0.258 inches. Heavy metal construction provides high mass and vibration damping in small-bore applications where chatter control is critical.

This boring bar is suited for small-diameter internal boring work on production or job-shop turning centers. It is typically used in applications requiring tight tolerances in short-reach bores where rigidity and insert stability are priorities. The coolant-through design, with a 0.094-inch coolant hole diameter, supports directed coolant delivery to the cutting zone, extending insert life and improving chip evacuation in ferrous and non-ferrous materials. Machinists and tooling technicians working with Swiss-style or conventional CNC lathes will find this bar applicable to a range of finish and semi-finish boring passes.

Key Features

• Top Notch series L-MNE toolholder style for rigid, repeatable insert seating
• Clamp-style insert holding method compatible with N.1L inserts
• Coolant-through design with 0.094-inch coolant hole for directed chip and heat management
• Heavy metal shank construction for enhanced vibration damping in small-bore work
• Right-hand cut orientation for standard lathe setup
• Center-to-cutting-edge of 0.258 inches for precise bore geometry control

Compatibility

Designed for use with N.1L series inserts in KENNAMETAL Top Notch tooling systems. Insert clamping is mechanical clamp-style; no additional adapter is required for standard N.1L insert profiles.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the spindle fully stopped and machine power isolated per shop lockout/tagout procedures. Ensure the shank is clamped securely in a compatible boring bar holder sized for a 5/16-inch shank before operation. Coolant-through connections should be verified for proper sealing before running the coolant system. Follow the insert manufacturer torque and seating guidelines when indexing or replacing N.1L inserts.