Turning Inserts
CNMG Carbide Turning Inserts
Negative 80° diamond turning inserts in ISO 1832 standard sizes — the most widely used insert shape for steel, stainless steel and cast iron turning.
Product Overview
CNMG inserts are negative 80° diamond-shaped indexable turning inserts with a 0° clearance angle, available in standard ISO sizes CNMG120404 / 120408 / 120412 and more. They deliver strong cutting edges with two-sided use (8 cutting edges per insert), making them the most cost-efficient choice for external and internal turning of steel, stainless steel and cast iron in roughing, semi-finishing and finishing operations.
Key Features
- 8 cutting edges per insert (two-sided negative design) — lowest cost per edge
- CVD multilayer coating for wear resistance and thermal stability
- Stable substrate with consistent hardness across batches
- Edge passivation reduces chipping and extends tool life
- Full size range: CNMG0903, 1204, 1606, 1906 series
- Custom grades and private-label packaging available
Applications
Factory-direct — produced in our own carbide plant
ISO 1832 dimensional compliance, batch inspected
OEM / ODM support for distributors and brands
Application support for grade and parameter selection
Technical Specifications
| Item | Specification |
|---|---|
| Insert Shape | 80° Diamond (C type), negative geometry |
| Standard Sizes | CNMG120404 / CNMG120408 / CNMG120412 (ISO 1832) |
| Inscribed Circle (IC) | 12.7 mm (per ISO 1832) |
| Thickness (S) | 4.76 mm |
| Nose Radius (r) | 0.4 / 0.8 / 1.2 mm |
| Coating | CVD (MT-TiCN + Al2O3 + TiN) / PVD / Uncoated |
| Applications | External & internal turning, facing, profiling |
| Workpiece Materials | Carbon steel, alloy steel, stainless steel, cast iron |
| MOQ | 10 pcs (standard sizes) |
| Lead Time | 3-7 days standard, 15-30 days custom |
* Specifications subject to change. Contact us for the current datasheet.
FAQ
Questions Buyers Ask
What does CNMG stand for?
Per ISO 1832: C = 80° diamond shape, N = negative clearance angle (0°), M = tolerance class (medium, ±0.08 to ±0.13mm), G = chip breaker/face type. CNMG120408: IC 12.7mm, thickness 4.76mm, nose radius 0.8mm.
What is the difference between CNMG120404, 120408 and 120412?
The last two digits are the nose radius: 04 = 0.4mm (finishing, light cuts), 08 = 0.8mm (general purpose), 12 = 1.2mm (roughing, heavy cuts, stronger edge).
Which CNMG grade should I use for stainless steel?
For stainless steel (M group), use PVD-coated grades with sharper edges — they reduce work hardening and built-up edge. For carbon steel (P group), CVD-coated grades provide better wear resistance at higher speeds. Send us your material and operation and we will recommend the grade.
Can CNMG inserts be used for internal turning?
Yes, CNMG inserts fit standard external and internal turning holders (e.g. MCLNR/MWLNR holders for CNMG 1204 inserts). The 80° diamond shape provides good clearance for most internal bores.
Do you offer private label for CNMG inserts?
Yes — OEM/ODM with private-label packaging, custom grades and laser marking per your specification. Standard sizes MOQ 10 pcs.
APPLICATIONS
Where It's Used
Typical machining operations and workpiece materials for CNMG Carbide Turning Inserts. Contact us with your operating parameters for grade selection support.
External turning of steel shafts
Internal bore turning
Face turning of flanges
Cast iron machining
Stainless steel turning
Heavy roughing operations
Interested in CNMG Carbide Turning Inserts?
Factory-direct pricing, OEM/ODM options and lead times — send your spec and volume, get a quote within 24 hours.