Sandvik Coromant 7861055 Turning Insert VBMT332-PF 4425

Product Description

The SANDVIK COROMANT 7861055 is a solid carbide turning insert in the CoroTurn 107 series, designed for precision finishing operations on steel and cast iron workpieces. It carries the ANSI insert code VBMT332 and ISO code VBMT 16 04 08-PF 4425. The insert features a 35-degree diamond (rhombic) shape with a neutral hand orientation, a 3/8 inch inscribed circle, and a 1/32 inch corner radius. The CVD-applied multilayer coating — Al2O3, TiN, and TiCN — delivers high wear resistance with moderate toughness, making this insert well suited for continuous and semi-continuous steel turning at finishing feed rates and depths of cut.

This insert is intended for light finishing passes on steel (ISO material group P) and secondary use on cast iron (ISO material group K). The PF chip breaker geometry controls chip formation at low feed rates and shallow depths, reducing built-up edge and maintaining surface finish quality. It is commonly installed in CoroTurn 107 toolholders that accept VBMT-style inserts. Machinists running CNC lathes, turret lathes, or manual turning centers will find this insert appropriate for achieving tight tolerances and fine surface finishes on medium to small steel components.

Key Features

• 35-degree diamond (rhombic) insert shape — ANSI code VBMT332, ISO code VBMT 16 04 08
• CVD multilayer coating: Al2O3, TiN, and TiCN for wear resistance on steel
• PF chip breaker geometry optimized for steel finishing operations
• Neutral hand insert — compatible with both right-hand and left-hand holder configurations
• Positive side clearance (5-degree relief angle) reduces cutting forces on finishing passes
• Two cutting edges per insert; screw and clamp holding methods supported

Compatibility

Designed for use in CoroTurn 107 series toolholders accepting VBMT-style inserts. Primary workpiece material is steel (ISO P); secondary workpiece material is cast iron (ISO K). Insert holding method is compatible with clamp and screw-style toolholder systems.

Installation Notes

Installation is performed by a machinist or toolroom technician. Power down and lock out the machine spindle before indexing or replacing inserts. Use the appropriate torque wrench and insert screw for the specific CoroTurn 107 toolholder to avoid over-torquing the clamping screw. Inspect the insert seat and chip breaker pocket for debris before seating a new insert, as contamination can affect seating accuracy and cutting geometry.