CNMG 120404-TM OS8225 Carbide Turning Insert

The CNMG 120404-TM OS8225 is a negative-rake turning insert designed for precision machining in CNC and conventional lathes. Its 80° rhombic shape and strong cutting edges ensure stability, making it suitable for roughing and finishing tasks. With a corner radius of 0.4 mm, it is ideal for applications that require fine surface finishes and tight dimensional control.

The insert is produced in the OS8225 grade, which provides a balanced combination of wear resistance and toughness. The TM chipbreaker enhances chip control, improves surface quality, and reduces cutting forces. The CNMG 120404-TM OS8225 is compatible with common external turning holders such as MCLNR, PCLNR, and DCLNR, ensuring broad applicability.

This insert is widely used in automotive, mold making, and general engineering, offering reliable performance under medium machining conditions.

Code Breakdown:

• C – Insert shape: 80° rhombic

• N – Clearance angle: 0° (negative rake)

• M – Tolerance class (medium)

• G – Insert with hole and chipbreaker

• 12 – Insert size: 12 mm

• 04 – Thickness: 4.76 mm

• 04 – Corner radius: 0.4 mm

• TM – Chipbreaker for medium machining

• OS8225 – Grade optimized for steels and stainless steels

Key Features:

• CNMG-style 80° rhombic turning insert

• Radius 0.4 mm, thickness 4.76 mm

• TM chipbreaker for chip control and finish

• Grade OS8225 – balanced wear resistance and toughness

• Negative rake geometry for stability

• Fits holders: MCLNR, PCLNR, DCLNR

• Ideal for medium machining of steels and stainless steels

Grade Information (OS8225):

• Coating: PVD, copper color

• Application: general milling and turning of steels, stainless steels, cast irons

• Best for: stainless steel turning and milling

• Material hardness: HRC <30

• Cutting speed: 120–220 m/min