WNMG ...-MA RT250M: Reliable turning of stainless steel
The indexable insert WNMG ...-MA in grade RT250M is the preferred choice for the process-safe turning of stainless steels. The combination of a tough M20-M30 carbide substrate and a wear-resistant PVD coating supports efficient machining operations. The MA chipbreaker geometry is perfectly suited for medium machining, while the 80-degree trigon shape with its six cutting edges ensures high flexibility and outstanding cost-efficiency.
Suitable materials

Technical data
- Insert shape: WNMG (80° trigon)
- Processing: Medium machining
- Cutting condition: Continuous and lightly interrupted cuts
- Application: Stainless steel
- Grade: RT250M (PVD-coated M20-M30 carbide)
- Packaging unit: 10 pieces
Dimensions of WNMG ...-MA RT250M
|
Item Nr. |
r |
L |
I.C |
S |
d |
| WNMG 080404-MA RT250M |
1661641 |
0,4 |
8,7 |
12,7 |
4,76 |
5,16 |
| WNMG 080408-MA RT250M |
1661642 |
0,8 |
8,7 |
12,7 |
4,76 |
5,16 |
Cutting data
|
Stainless Steel |
|
Vc (m/min) |
fn (mm/U) |
ap (mm) |
| WNMG 080404-MA RT250M |
100-200 |
0,1-0,3 |
1-3,5 |
| WNMG 080408-MA RT250M |
100-200 |
0,1-0,3 |
1-3,5 |
Applications
The WNMG turning insert featuring the MA geometry is specifically designed for turning operations in stainless materials. It excels in medium machining applications, delivering a convincing performance in both continuous and slightly interrupted cuts. The basic shape is highly suitable for external and internal turning operations that demand a robust cutting edge.
Special features
The trigonal basic shape provides six usable cutting edges, offering an excellent price-performance ratio for professional users. The tough RT250M carbide grade effectively absorbs mild shocks during the cutting process, while the thermally stable PVD coating limits premature edge wear when machining stainless steel. This creates perfect conditions for smooth production workflows without frequent tool changes.