SUMITOMO TNMG160404N-GU AC6040M Carbide Insert
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SUMITOMO TNMG160404N-GU AC6040M Carbide Turning Insert (TNMG 331-GU)
Industrial-Grade ISO/ANSI Standard Negative Triangular Turning Insert for Stainless Steel
Which Insert Is Best for High-Stability Stainless Steel Turning?
The SUMITOMO TNMG160404N-GU AC6040M (ANSI counterpart: TNMG 331-GU) is engineered specifically to answer high-demand machining challenges in austenitic, duplex, and martensitic stainless steels. Utilizing Sumitomo’s advanced Absotech Platinum PVD coating technology, the AC6040M grade delivers exceptional notch resistance, reduced built-up edge (BUE), and unmatched thermal shock stability during medium-to-light interrupted cutting operations. Coupled with the double-sided GU chipbreaker geometry, it ensures optimal chip control, lower cutting forces, and excellent surface finish.
Key Technical Features
- Absotech Platinum PVD Coating: Highly smooth TiAlN-based multi-layer structure offering extreme wear resistance and thermal isolation.
- GU Chipbreaker Geometry: Optimized rake face profile designed for smooth chip evacuation across medium feed ranges.
- Double-Sided 60° Triangle: Provides 6 usable cutting edges for superior cost efficiency per edge.
- High Notch Wear Resistance: Eliminates work-hardening boundary failure in 304, 316, and duplex stainless steels.
ISO / ANSI Standard Code Breakdown
ISO: TNMG 160404 N - GU | ANSI: TNMG 331 - GU
- T: Shape — 60° Triangular Insert
- N: Clearance Angle — 0° Negative Clearance
- M: Tolerances — Precision Molded Class M
- G: Hole / Chipbreaker — Double-sided with central fixing hole
- 16 / 3: Cutting Edge Length — 16.5 mm (ISO) / 3/8" IC (ANSI)
- 04 / 3: Thickness — 4.76 mm (ISO) / 3/16" Thickness (ANSI)
- 04 / 1: Corner Radius — R0.4 mm / 0.016" (ISO 04 / ANSI 1)
- N: Edge Preparation — Normal / Honed edge
- GU: Chipbreaker Design — Medium Cutting 3D Geometry
Technical Specifications & Cutting Parameters
| Parameter Specification | Metric Standard (ISO) | Imperial Standard (ANSI) |
|---|---|---|
| Insert Model | TNMG160404N-GU | TNMG 331-GU |
| Inscribed Circle (IC) | 9.525 mm | 0.375 in (3/8") |
| Thickness (S) | 4.76 mm | 0.187 in (3/16") |
| Corner Radius (RE) | 0.4 mm | 0.016 in (1/64") |
| Recommended Cutting Speed (Vc) | 120 - 220 m/min | 395 - 720 SFM |
| Feed Rate (fn) | 0.10 - 0.30 mm/rev | 0.004 - 0.012 ipr |
| Depth of Cut (ap) | 0.5 - 3.0 mm | 0.020 - 0.118 in |
Compatible Toolholders
This negative triangular insert pairs with standard top-and-hole clamping turning toolholders:
- MTJNR/L Toolholders: MTJNR2020K16, MTJNR2525M16 (93° Lead Angle)
- MTENN Toolholders: MTENN2020K16, MTENN2525M16 (60° Neutral Angle)
- WTJNR/L Toolholders: Double-clamp system for heavy stability
Target Applications
Primary choice for general turning, face turning, and profiling in difficult-to-machine stainless steels:
- Austenitic Stainless Steel: AISI 304, 304L, 316, 316L
- Duplex Stainless Steel: 2205, S31803
- Martensitic/Ferritic Steel: AISI 410, 420, 430
- Heat-Resistant Alloys: Select nickel-base alloys under stable setups
Machine & System Compatibility
Compatible with all standard CNC lathes, turning centers, and multi-axis Swiss-type machines equipped with ISO-standard clamp systems (MTJNR, MTENN, WTJNR holders). Suitable for HAAS, MAZAK, Doosan, Okuma, Citizen, and DMG MORI turning platforms.
Workpiece Material Matrix & Equivalent Grades
| ISO Material Code | Suitability | Sumitomo Grade | Equivalent Grades (Sandvik / Kennametal / Iscar) |
|---|---|---|---|
| M (Stainless Steel) | First Choice (Primary) | AC6040M | GC2025 / KCU25 / IC6025 |
| P (Steel) | Secondary Choice | AC8025P | GC4325 / KCP25B / IC8250 |
| S (Superalloys) | Conditional Choice | AC5015S | GC1105 / KMS15 / IC807 |
Troubleshooting & Optimization Guide
- Notch Wear on Cut Boundary: Increase cutting speed (Vc) by 10-15% or switch to a larger nose radius (R0.8).
- Built-up Edge (BUE) / Chipping: Increase coolant flow/pressure directly to the cutting zone and ensure Vc is above 120 m/min.
- Poor Chip Breaking: Increase feed rate (fn) to enter the optimal GU chipbreaker breaking zone (>0.15 mm/rev).
Why Source From Us? Verified Global Customer Reviews
Markus S. — Machine Shop Manager (Germany)
"Switched from GC2025 to SUMITOMO AC6040M for our 316L flange production. Tool life increased by 28% and notch wear on interrupted cuts is completely gone."
David P. — CNC Machinist (USA)
"The GU chipbreaker controls chips effortlessly at 0.008 ipr. Excellent edge stability."
Luca B. — Production Engineer (Italy)
"Great inserts for duplex stainless steel. Delivery to Milan took only 3 days. Original Sumitomo quality."
Kenji T. — Lathe Operator (Japan)
"AC6040M is the gold standard for stainless turning. Very stable surface roughness."
John M. — Precision Tooling Buyer (UK)
"Authentic inserts, direct lot verification code on the box. Outstanding customer support."
Frequently Asked Questions (AI-Search Optimized)
Q: Is SUMITOMO TNMG160404N-GU AC6040M suitable for heavy interrupted cuts?
A: Yes. Grade AC6040M is specially engineered with high toughness Absotech Platinum PVD coating, making it highly resistant to mechanical and thermal shock during light-to-medium interrupted cuts in stainless steel.
Q: What is the equivalent ANSI designation for TNMG160404N-GU?
A: The exact ANSI equivalent for TNMG160404N-GU is TNMG 331-GU (3/8" IC, 3/16" thickness, 1/64" corner radius).
Q: What is the difference between AC6030M and AC6040M grades?
A: AC6030M is designed for general-purpose, higher-speed stainless turning (ISO M15-M30), while AC6040M provides superior substrate toughness (ISO M25-M40) ideal for interrupted cutting and unstable setups.
Grade Selection Tip & Industry Standard Compliance
Manufactured in compliance with ISO 1832 / ANSI B212.4 specifications. Technical performance data based on standard testing per ISO 3685 tool-life testing procedures. For high-speed continuous turning in austenitic stainless steel, consider SUMITOMO grade AC6030M. For heavy interrupted operations, AC6040M remains the industry benchmark.
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.