Hertel 8851987 Turning Insert VNMG331BH HT115CR Cermet

Product Description

The HERTEL 8851987 is a VNMG331BH HT115CR cermet turning insert designed for precision external turning operations on CNC and manual lathes. This uncoated cermet insert features a 35-degree diamond shape (V-style) with a neutral hand orientation and a positive rake angle of 15 degrees. The 3/8-inch inscribed circle and 1/64-inch corner radius make it suitable for finishing and semi-finishing passes where tight tolerances and surface finish quality are critical. Machinists and toolroom operators select cermet grades like HT115CR for their hardness and wear resistance when cutting steel, cast iron, and similar ferrous materials at moderate to high cutting speeds.

This insert is intended for use in VNMG-compatible toolholders on production turning centers, CNC lathes, and manual turning equipment. Typical applications include finishing passes on steel shafting, bearing surfaces, and close-tolerance turned components where dimensional accuracy and low surface roughness are required. The G-style chip breaker geometry promotes controlled chip formation during light-to-moderate depth-of-cut operations. This is a trade-quantity item with a minimum order quantity of 10 inserts per order.

Key Features

• Cermet insert material (HT115CR grade) provides high hardness and wear resistance for ferrous finishing applications
• 35-degree diamond insert shape (V) delivers sharp cutting geometry for precise turning
• Positive rake angle of 15 degrees reduces cutting forces and heat generation
• G chip breaker promotes controlled chip evacuation during finishing and semi-finishing cuts
• Neutral hand orientation fits both right-hand and left-hand toolholder configurations
• Uncoated cermet substrate maintains consistent edge sharpness without coating buildup at the cutting edge

Compatibility

Designed for use in VNMG-style toolholders that accept a 3/8-inch inscribed circle insert with a 0.150-inch hole diameter and clamp or pin holding method. Verify toolholder insert pocket specifications against VNMG331 insert geometry before installation.

Installation Notes

Insert seating and clamping should be performed by a qualified machinist or toolroom technician following the toolholder manufacturer's clamping torque guidelines. Ensure the machine spindle is fully stopped and all motion has ceased before indexing or replacing inserts. Inspect the insert pocket seat and locating pin for wear or debris before seating a new insert, as contamination can cause improper seating and premature edge failure. Follow shop safety protocols for handling sharp cutting inserts.