CNMG120404 Insert: Dimensions, Grades & Cross References

The CNMG120404 is an ISO 1832 indexable turning insert: an 80° rhombic (C), 0° clearance, chipbreakers on both faces (double-sided), with inscribed circle d1 12.7 mm (0.5 in), thickness s 4.76 mm and 0.4 mm nose radius rε. Verify the full ordering code against the manufacturer catalogue before ordering.

Specification table

Source: ISO 1832 designation standard (geometry positions 1–8). Brand-specific rows below cite their manufacturer catalogue individually.

Cross-brand geometric interchange

Under ISO 1832, every insert carrying the core designation CNMG120404 shares identical geometry — shape, inscribed circle, thickness and nose radius — regardless of manufacturer. Letters after a dash (chipbreaker patterns, grade numbers) affect chip control and application band, not the pocket geometry, and are marked PARTIAL.

Match levels: FULL = same geometry and equivalent grade · PARTIAL = geometry matches, chipbreaker/grade differs · VERIFY = commonly quoted, confirm against the target catalogue.

Grade cross-reference (ISO 513)

Geometry swaps are safe; grade swaps need review. Grades are mapped only within the same ISO 513 workpiece group and application band, and every mapping is cited. Verified catalog mappings for this geometry are added row by row.

Grades catalogued for CNMG120404

These are the manufacturer's own grade offerings for this geometry, each linked to its grade record.

Cross-brand grade equivalents

Applications & cutting conditions

Selection notes

• ▸Geometry first, grade second. The same ISO core code is a drop-in pocket fit across brands; the chipbreaker suffix and grade decide performance and must be matched to the cut.
• ▸Nose radius is a trade-off. A larger rε strengthens the edge and allows higher feeds but raises radial cutting forces and vibration risk; smaller radii suit finishing, fine detail and slender setups.
• ▸Match clearance to the holder. Positive-clearance codes (B/C/P…) require the matching positive toolholder; 0° N inserts seat on negative holders and offer twice the edges.
• ▸Tolerance class for the job. G and tighter classes suit precision and finishing; M-class moulded inserts are the economical default for general turning.
• ▸Pick the chipbreaker for your feed band. Roughing and finishing geometries are not interchangeable in practice even when the core code is identical.
• ▸Toughness vs wear resistance. Tough grades resist interrupted cuts and scale; hard, wear-resistant grades suit stable, high-speed finishing — choose within the same ISO 513 group.

Frequently asked questions