Korloy MRMN300-M NC3120 3mm Full Radius R1.5 CVD Insert for Steel & Cast Iron (10pcs)
Price shown is a starting point. Contact us for a precise quote based on your requirements.
The Original Korloy MRMN300-M NC3120 is a high-performance 3.0mm Full Radius (R1.5) Profiling Insert, precision-engineered for the versatile machining of both Steel (P) and Cast Iron (K). Equipped with the advanced NC3120 CVD coating, this insert excels in maintaining edge integrity under the abrasive conditions of cast iron while providing the heat resistance needed for high-speed steel turning. The Full Radius (Round Nose) geometry combined with the -M (Medium) chipbreaker ensures smooth chip flow and reduced vibration during 3D contouring.
Universal Machining Excellence: NC3120 is Korloy’s "Multi-Purpose" CVD grade. It features an optimized multi-layer coating that prevents peeling and micro-chipping, making it far more reliable than standard grades when switching between different carbon steels and ductile iron workpieces.
Technical Specifications:
| Brand | Korloy (100% Genuine) |
| ISO Code | MRMN300-M |
| Insert Shape | Full Radius (Round Nose) |
| Width / Radius | 3.0 mm / R1.5 |
| Grade | NC3120 (Steel & Cast Iron Specialist) |
Core Performance Benefits:
- Steel & Cast Iron Optimized: A rare grade that handles the toughness of steel and the abrasiveness of cast iron with equal efficiency.
- R1.5 Full Radius Stability: Designed for flawless 3D profiling, deep circular grooves, and large corner transitions without chatter.
- Enhanced CVD Coating Layer: Provides superior resistance to crater wear and thermal cracking compared to PVD alternatives.
- -M Chipbreaker Control: Precisely manages chip formation across a wide range of feed rates, preventing workpiece marring.
Recommended Cutting Parameters:
| Material Group | Cutting Speed (Vc) | Feed Rate (f) |
|---|---|---|
| Carbon Steel (S45C) | 150 - 250 m/min | 0.08 - 0.22 mm/rev |
| Alloy Steel (SCM440) | 120 - 210 m/min | 0.06 - 0.18 mm/rev |
| Cast Iron (GG25/FC250) | 130 - 230 m/min | 0.10 - 0.25 mm/rev |
Compatible Tool Holders:
Precision 3.0mm seat fit for standard MGEHR/MGIVR systems:
- External Holders: MGEHR 2020-3 / 2525-3 / 3232-3
- Internal Holders: MGIVR 2520-3 / 3125-3
Machinist Tip: Why Choose NC3120?
Understanding where NC3120 fits in your production:
The Hybrid Choice. Use this grade if your shop processes both steel and cast iron. It offers better toughness than NC3020 and significantly better wear resistance than PC5300 in these materials.
Pure Steel Specialist. Optimized strictly for high-speed, continuous steel turning. It is slightly harder but more prone to chipping when encountering the sand inclusions common in cast iron.
Pro Advice: For MRMN300-M NC3120, the 3.0mm width is highly versatile. If you are machining cast iron, ensure a consistent feed rate to prevent work hardening of the surface, which can cause premature flank wear.
Packaging: 10 pieces per box.
Korloy MRMN300-M price, 3mm full radius insert for cast iron turning, NC3120 vs NC3020 performance, R1.5 round nose profiling insert, MRMN300-M cutting speed steel
Technical FAQ & Buying Guide
Absolutely. Our CNC carbide inserts (including CNMG, WNMG, DNMG, and APMT series) are manufactured strictly adhering to international ISO/ANSI specifications. A CNMG 120408 from OYYU BEYOND will flawlessly fit any standard turning tool holder or indexable tool from major global brands like Sandvik Coromant, Kennametal, Iscar, Walter, or SECO, providing a highly cost-effective premium alternative without sacrificing tolerance or tool life.
We offer optimized CVD and PVD multi-layer coatings for different ISO material groups:
- For Carbon/Alloy Steel (ISO P): Choose our thick multi-layer CVD coated grades (e.g., Al2O3 + TiN). They provide exceptional crater wear resistance and thermal barriers during high-speed dry or wet roughing.
- For Stainless Steel (ISO M): Choose our nano-structured PVD coated grades with sharp, positive chipbreakers (like -TM or -MA). This combination prevents work hardening and effectively controls sticky chips.
The optimal cutting parameters vary depending on the workpiece hardness and operation type:
- For General Steel Turnings: Recommended cutting speed ($V_c$) ranges from 150 to 280 m/min, with a feed rate ($f$) of 0.15 to 0.45 mm/rev.
- For Stainless Steel Finishing: Recommended cutting speed ($V_c$) is 120 to 200 m/min, with a feed rate ($f$) of 0.10 to 0.25 mm/rev.Always adjust parameters based on early wear patterns: increase $V_c$ if built-up edge occurs, or reduce $V_c$ if severe flank wear is observed.
Yes, we support machine shops, distributors, and global buyers with tiered wholesale pricing and competitive volume discounts. We also provide OEM custom manufacturing solutions for tool holders and carbide inserts based on your technical drawings. Contact our team to request a quick B2B quotation.
We provide secure worldwide express shipping (via DHL, FedEx, and UPS) with specialized, vibration-proof industrial packaging to ensure tools arrive in perfect condition. In-stock items are dispatched within 24-48 hours, while custom or bulk orders typically have a stable lead time of 15-25 days.
All our cutting tools and tool holders are manufactured strictly in accordance with ISO 9001 and international industrial standards. Every batch undergoes 100% rigorous quality control testing using high-precision optical measuring equipment to ensure reliable tool life and stable performance in continuous mass production.