Ultra-dex 920-000-153 Indexable Boring Bar Solid Carbide

Product Description

The ULTRA-DEX 920-000-153 is a solid carbide indexable boring bar designed for internal turning and boring operations on CNC lathes and manual turning centers. It accepts CPMT 21.51 indexable inserts secured by a screw-clamp system, delivering consistent cutting geometry and fast insert changes. The bar features a 3/8-inch shank diameter, a minimum bore diameter of 0.4 inches, and a -5 degree lead angle with right-hand cut orientation. Overall length is 6 inches. Solid carbide construction provides greater rigidity and vibration resistance compared to steel-shank alternatives, making it well suited for small-diameter, deep-bore applications where deflection must be minimized.

This boring bar is used in precision machining environments including job shops, production turning cells, and tool rooms. It is appropriate for boring small internal diameters in ferrous and non-ferrous workpieces. The 0.4-inch minimum bore diameter makes it a practical choice for tight-tolerance internal finishing passes where clearance is limited. Right-hand cut orientation suits standard lathe spindle rotation. Machinists and CNC programmers working with small-diameter bores will find the CPMT 21.51 insert compatibility useful for sourcing replacement inserts from multiple manufacturers.

Key Features

• Solid carbide shank for improved rigidity and vibration damping in small-bore applications
• 0.4 inch minimum bore diameter for tight internal clearances
• 3/8 inch shank diameter for standard boring bar holders and turrets
• Right-hand cut with -5 degree lead angle for controlled chip direction
• Screw-clamp insert retention for repeatable seating of CPMT 21.51 inserts
• 6 inch overall length suitable for moderate reach boring operations

Compatibility

Designed to accept CPMT 21.51 indexable inserts. Fits standard 3/8-inch boring bar holders and turret blocks used on CNC and manual lathes. Verify holder bore diameter and insert pocket geometry before installation.

Installation Notes

Installation is performed by qualified machinists or CNC setup technicians. Ensure the machine spindle is fully stopped and the control is in an E-stop or locked-out state before mounting or adjusting the boring bar. Secure the shank firmly in the tool holder to the holder manufacturer's specified clamping torque to prevent pullout during cutting. Confirm insert seating and screw engagement before taking the first cut; a loose insert can damage the pocket and the workpiece.