Korloy TNMG160404-HM NC3020 (TNMG 331-HM) Steel Turning Insert for Medium Cutting (10pcs)
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The Original Korloy TNMG160404-HM NC3020 (ANSI: TNMG 331-HM) is a high-performance, double-sided Triangular Turning Insert engineered for General Steel Machining (P-Group). Featuring the industry-proven NC3020 CVD Coating, this insert excels in high-speed operations where heat resistance and crater wear protection are paramount. The HM Chipbreaker is specifically designed for medium cutting ranges, providing excellent chip breaking and edge reliability across a wide variety of carbon and alloy steels.
Medium Cutting Workhorse: The HM geometry balances sharpness with edge strength. It is the perfect "all-rounder" for workshops processing 1045, 4140, and 8620 steels, offering a stable cutting action and consistent tool life even during long production runs.
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 | NC3020 (Premium CVD for Steel) |
Core Performance Benefits:
- Advanced CVD Multi-Layer Coating: Optimized Al2O3 and TiCN layers provide a formidable barrier against high cutting temperatures.
- HM Geometry: Features a reinforced land that prevents edge chipping while maintaining high chip-breaking efficiency.
- Precision Finishing: The 0.4mm (331) radius is ideal for achieving tight tolerances and fine surface finishes on medium-sized workpieces.
- 6 Usable Edges: Double-sided design offers a highly economical solution for high-volume manufacturing.
Recommended Cutting Parameters:
| Material Group | Cutting Speed (Vc) | Feed Rate (fn) | Depth of Cut (ap) |
|---|---|---|---|
| Carbon Steel (1045/A3) | 180-350 m/min (590-1150 sfm) | 0.10-0.35 mm/rev (.004-.014 ipr) | 0.5-3.5 mm (.020-.138") |
| Alloy Steel (4140/SCM440) | 150-300 m/min (490-985 sfm) | 0.10-0.30 mm/rev (.004-.012 ipr) | 0.5-3.0 mm (.020-.118") |
Compatible Tooling Systems:
- External Lathe Holders: MTJNR 2020K16 / MTJNR 2525M16 (ANSI 12-4B / 16-4D)
- Internal Boring Bars: S25S-WTJNR16 / S32T-WTJNR16
Machinist Tip: Choosing your TNMG1604 Geometry
How the HM chipbreaker fits into your workflow:
The Generalist. Use the HM for 80% of your steel turning. It handles varying depths of cut and provides reliable chip breaking at both high and medium feed rates.
Switch to the HA geometry if you are working with very soft, gummy steel and need to prevent burrs. Stick with HM for harder alloy steels where edge strength is necessary to prevent premature wear.
Pro Advice: NC3020 is a high-speed grade. If you experience "chipping" at the edge, you may be running too slow, causing built-up edge. Increase your Vc (cutting speed) to take full advantage of the CVD coating's lubricity.
Packaging: 10 pieces per box.
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