Kennametal 1270950 Indexable Boring Bar 0.275 in Min Bore

Product Description

The KENNAMETAL 1270950 is an indexable boring bar designed for precision internal turning operations on CNC lathes and turning centers. Built on the E03MSTLDR128 platform, this toolholder features a solid carbide shank for maximum rigidity and vibration resistance in small-bore applications, paired with a steel head that secures the insert via a screw-clamp holding method. The bar opens bores as small as 0.275 inches and reaches a maximum bore depth of 1.875 inches, making it well suited for tight, deep-bore work. It carries a right-hand cut orientation and a 5-degree lead angle with a positive rake geometry to reduce cutting forces and support clean chip evacuation in small-diameter bores.

This boring bar is intended for use in precision machining environments where small internal diameters demand a stiff, compact toolholder. It is a fit for production and job-shop turning applications where consistent bore finish and dimensional accuracy are required. The coolant-through design, with a 0.040-inch coolant hole diameter, supports directed cutting fluid delivery to the insert tip, which is particularly valuable when machining deep bores or difficult-to-cut materials where heat and chip control are critical concerns. Licensed machinists and CNC programmers working on small-component turning will find this bar appropriate for both roughing and finishing passes within its bore range.

Key Features

• Solid carbide shank provides high rigidity and dampens vibration in small-bore, long-reach applications
• Coolant-through design with 0.040-inch coolant hole delivers cutting fluid directly to the cutting zone
• Screw-clamp insert holding method ensures secure indexing and repeatable tool nose position
• Positive rake geometry at 5 degrees reduces cutting forces and supports efficient chip flow
• Right-hand cut orientation with 5-degree lead angle for standard internal turning setups
• Compatible with TD-style inserts with a 0.160-inch inscribed circle for flexible insert sourcing

Compatibility

This toolholder accepts TD-style inserts with an inscribed circle of 0.160 inches and an insert thickness of 0.047 inches. It is designated as Series F, Toolholder Style FCBI. No additional compatible model or system data was provided in the product information.

Installation Notes

Installation and setup should be performed by a qualified machinist or CNC tooling technician. Ensure the machine spindle is fully stopped and the turret is in a safe index position before mounting or removing the boring bar. The toolholder shank diameter is 0.1875 inches; verify that the tool block or bore-bar holder on the turret is sized to match before tightening. Do not exceed the maximum bore depth of 1.875 inches, and confirm coolant line connections are secure if using the through-coolant feature to avoid pressure loss at the cutting zone.