Korloy TNMG160404-HM NC3030 (TNMG 331-HM) Tough Steel Turning Insert (10pcs)
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The Original Korloy TNMG160404-HM NC3030 (ANSI: TNMG 331-HM) is a high-toughness Triangular Turning Insert specifically engineered for Steel Machining (P-Group) under unstable conditions. Featuring the specialized NC3030 CVD Coating, this insert provides industry-leading resistance to chipping and thermal shock. The HM (Medium Cutting) Chipbreaker with its 0.4mm corner radius is the ideal solution for precision turning on workpieces with interrupted surfaces, such as shafts with keyways or hex bolts.
Built for the Tough Jobs: Unlike general-purpose grades that may crack during interrupted cuts, the NC3030 grade features a reinforced substrate that absorbs impact. It is your best insurance policy against sudden edge failure when machining rough or uneven steel surfaces.
Technical Specifications (Metric & Imperial):
| ISO Designation | TNMG 160404-HM |
| ANSI Designation | TNMG 331-HM |
| Inscribed Circle (IC) | 9.525 mm / (3/8") |
| Thickness (S) | 4.76 mm / (3/16") |
| Corner Radius (r) | 0.4 mm / (1/64") |
| Grade | NC3030 (Impact Resistant CVD for Steel) |
Core Performance Benefits:
- Maximum Toughness: Specialized substrate prevents fracture during heavy-duty interruptions or fluctuating loads.
- Advanced CVD Coating: Thick Al2O3 layer ensures tool longevity by resisting heat buildup, even during dry machining.
- Precision Tip: The 0.4mm (331) radius allows for detailed semi-finishing and fine tolerances in unstable setups.
- Multi-Edge Economy: 6 cutting edges (3 per side) provide exceptional cost-per-part efficiency.
Recommended Cutting Parameters:
| Material Group | Cutting Speed (Vc) | Feed Rate (fn) | Depth of Cut (ap) |
|---|---|---|---|
| Interrupted Steel (1045/4140) | 120-220 m/min (390-720 sfm) | 0.08-0.25 mm/rev (.003-.010 ipr) | 0.4-3.0 mm (.016-.118") |
| Low Rigid Setup (Steel) | 140-240 m/min (460-785 sfm) | 0.10-0.30 mm/rev (.004-.012 ipr) | 0.5-3.5 mm (.020-.138") |
Compatible Tooling Systems:
- External Precision Holders: MTJNR 2020K16 / MTJNR 2525M16 (ANSI 12-4B / 16-4D)
- Internal Boring Bars: S25S-WTJNR16 / S32T-WTJNR16
Machinist Tip: NC3020 vs. NC3030
Choosing the right grade for your steel job:
Best for Interrupted Cuts. Choose this grade for shafts with holes, hex shapes, or when the machine/workpiece lacks rigidity. It favors toughness over raw speed.
Best for Continuous Cuts. If your cut is stable (round bar, no gaps), NC3020 will offer higher wear resistance and allow for faster cutting speeds.
Pro Advice: When dealing with interruptions, use plenty of coolant to prevent thermal cracking, and slightly reduce your cutting speed (Vc) compared to continuous cutting to protect the cutting edge from impact fatigue.
Packaging: 10 pieces per box.
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