Kennametal 1152768 Indexable Boring Bar Left Hand E-stlp

Product Description

The KENNAMETAL 1152768 is a left-hand indexable boring bar in the E-STLP toolholder style, designed for internal turning and boring operations on CNC and manual lathes. Built from solid carbide, the bar accepts TP-series inserts secured by a screw-clamp holding method. It carries a minimum bore diameter of 12.19mm (0.480 inches) and an overall length of 152.4mm (6.000 inches). A 3/8-inch (9.53mm) shank diameter and a -5 degree lead angle define the cutting geometry. Through-coolant capability, via a 0.125-inch coolant hole, supports chip evacuation and tool life in deep-bore applications. This bar is suited for machinists and toolroom technicians working tight-tolerance bores in production or job-shop environments.

The 1152768 is applied in precision boring operations where left-hand cutting orientation is required, such as back-boring or specific fixturing setups on turning centers and engine lathes. Its through-coolant channel is particularly useful when machining deep cavities or difficult-to-machine alloys where heat buildup and chip packing are concerns. The neutral rake angle and 0-degree rake provide predictable cutting performance across a range of workpiece materials. A center-to-cutting-edge distance of 0.250 inches supports accurate bore sizing during setup.

Key Features

• Solid carbide construction for rigidity and vibration resistance in small-bore applications
• Left-hand cutting orientation for back-boring and specialized workholding setups
• Through-coolant design with a 0.125-inch coolant hole for chip flushing and thermal management
• Screw-clamp insert holding for secure, repeatable insert indexing
• Accepts TP-series inserts with a 1/4-inch inscribed circle and 3/32-inch insert thickness
• -5 degree lead angle with neutral rake for stable, controlled cutting action

Compatibility

Designed to accept TP-series (TP..) indexable inserts with a 1/4-inch inscribed circle and 3/32-inch thickness, as specified for the E-STLP toolholder style.

Installation Notes

Installation and tooling changes should be performed by a qualified machinist with the spindle fully stopped and machine power locked out per shop safety procedures. Confirm shank clamping torque meets the machine tool manufacturer specifications for a 3/8-inch boring bar holder before engaging the cut. Connect the through-coolant supply line to the shank inlet and verify flow before initiating the bore cycle. Insert indexing should follow the insert manufacturer seating procedure to ensure proper depth-of-cut and surface finish results.