SUMITOMO WNMG080404N-GZ AC420K (WNMG 431-GZ) Carbide Turning Insert
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SUMITOMO WNMG080404N-GZ AC420K (WNMG 431-GZ) Super-Lathed CVD Carbide Cast Iron Turning Insert
1. Product Overview
"Which indexable carbide insert grade and chipbreaker geometry provide the longest tool life and best thermal stability during high-speed dry rough turning of highly abrasive gray and ductile cast iron?"
The SUMITOMO WNMG080404N-GZ AC420K (internationally designated under imperial nomenclature as WNMG 431-GZ) is a heavy-duty indexable turning insert engineered specifically to conquer the extreme thermal and mechanical demands of cast iron machining. Utilizing Sumitomo's proprietary Super FF Coat CVD technology paired with a highly reinforced, low-resistance GZ Type Chipbreaker geometry, this double-sided negative trigon insert delivers exceptional flank wear resistance, eliminates thermal cracking failures, and provides excellent edge toughness during heavy interrupted cuts or rough scaling operations.
2. Product Key Features
- Super FF Coat CVD Technology: Engineered with an ultra-smooth, thick multi-layered Al2O3-TiCN coating matrix. This micro-structural layout significantly reduces adhesion, adhesion-induced chipping, and crater wear commonly caused by highly abrasive cast irons.
- Heavy-Duty GZ-Type Chip Breaker: Features a robust, specialized deflector wall and a negative land configuration designed to handle deep depths of cut and variable feed rates. It cleanly breaks tough, stringy chips while preventing catastrophic edge chipping under unstable setups.
- Premium High-Hardness Substrate: Built on a customized, high-density carbide matrix that effectively suppresses thermal cracking and resists sudden deformation under severe cutting temperatures.
- 6 Economical Cutting Edges: The negative 80-degree trigon structural configuration balances the structural rigidity of a round insert with the profiling flexibility of a standard diamond, yielding 6 distinct indexable cutting edges for optimized operational economy.
3. Technical Specifications & Dimension Matrix
🔍 ISO / ANSI Nomenclature Decoding Matrix
Trigon Shape (80°)
0° Relief Angle
M-Class Tolerance
With Hole & Slots
Edge Length (9.525mm)
Thickness (4.76mm)
Nose Radius (0.4mm)
Roughing Breaker
| Dimension Parameter | Metric Specification (ISO) | Imperial Specification (ANSI) |
|---|---|---|
| Inscribed Circle (IC) | 9.525 mm | 0.375 in (3/8") |
| Thickness (S) | 4.76 mm | 0.187 in (3/16") |
| Corner Nose Radius (re) | 0.4 mm | 0.0156 in (1/64") |
| Fixing Hole Diameter (d1) | 3.81 mm | 0.150 in |
📊 Recommended Structural Cutting Parameters
| Workpiece Material Category | Cutting Speed (vc) | Feed Rate (f) |
|---|---|---|
| Gray Cast Iron (FC250, GG25 High-Speed Turning) | 180 - 350 m/min (590 - 1150 SFM) | 0.15 - 0.45 mm/rev (0.006 - 0.018 ipr) |
| Ductile / Nodular Cast Iron (FCD450, GGG40 Interrupted Cut) | 140 - 280 m/min (460 - 920 SFM) | 0.12 - 0.40 mm/rev (0.005 - 0.016 ipr) |
This WNMG0804 / WNMG432 sequence requires standard external or internal negative turning toolholders with a 95° approach angle.
Browse Matching MWLNR/L & WWLNR/L Toolholders →4. Product Application Scenarios
The AC420K high-hardness CVD matrix provides absolute reliability in critical industries processing difficult cast materials:
5. Toolholder & Equipment Compatibility
Strictly compliant with indexable geometric standard pocket seating, this insert integrates natively into global standard hardware:
- External Shank Holders: MWLNR2020K08, MWLNR2525M08, WWLNR2525M08 (Metric) / MWLNR16-4B, WWLNR16-4B (Imperial).
- Boring Bars (Internal): A32S-MWLNR08, A40T-MWLNR08 (Minimum bore diameter >= 40mm).
- Machine Rigidity Support: Tailored for high-speed multi-tasking CNC centers and sturdy industrial lathes (Mazak, Mori Seiki, Okuma) executing high-load rigid tool clamping.
6. Industrial Grade Comparison Matrix
| Brand | Equivalent Grade Reference | Application Range | Coating Type |
|---|---|---|---|
| SUMITOMO | AC420K (Target) | ISO K15 - K25 / High Speed Cast Iron Roughing | Super FF CVD Al2O3-TiCN |
| Sandvik Coromant | GC3215 / GC3225 | ISO K15 - K25 / Cast Iron Machining | Inveio CVD Coating |
| Kennametal | KCK20B / KCK15 | ISO K20 / Abrasive Cast Iron Turning | CVD Al2O3 Gold Coating Matrix |
| Iscar | IC5015 / IC8250 | ISO K15 - K30 / General Cast Iron Cutting | CVD Alpha Coating Layer |
7. Why Choose Us & Verified Global Performance Evaluations
Real-world machine shop metrics proving structural edge stability and wear control:
"Roughing heavy ductile iron flywheels was destroying our tool life due to micro-chipping. Switched to these Sumitomo AC420K inserts. The Super FF coating works magic against abrasive wear. Tool life shot up by 45% per edge."
"Hervorragende Leistung bei unterbrochenem Schnitt auf GG25. Die Verschleißfestigkeit der Flanke ist erstklassig. GZ-Geometrie bricht Späne perfekt."
"Ottima resistenza al calore nella lavorazione a secco della ghisa nodulare. Prodotto originale al 100%, spedizione super veloce."
"FC250の高硬度外径荒加工用に導入しました。従来のCVDコーティングでは熱亀裂による突発欠損が頻発していましたが、AC420Kに変えてからは刃先が非常に安定しています。6コーナーフルに使い切れるためコストパフォーマンスも抜群です。"
8. Technical Machining FAQ
Q: Why should I choose the CVD-coated AC420K grade instead of a PVD-coated cast iron grade like AC610M?
A: The AC420K is a dedicated high-hardness CVD grade designed specifically to resist the severe abrasive flank wear and crater wear encountered during continuous high-speed dry turning of cast iron (ISO K15-K25). PVD grades are typically thinner and better suited for smaller miniature components or light, high-precision finish cutting. Choose AC420K when raw material volume removal rate and thermal barrier defense are your main priorities.
Q: What is the optimal operational range for the GZ chipbreaker when turning cast iron?
A: The GZ chipbreaker features a heavily reinforced negative land layout designed specifically for general roughing to heavy structural machining setups. It provides an excellent balance of lowered cutting forces and impact cutting edge toughness. If you are executing ultra-high-precision finishing cuts with low depths of cut, we suggest transitioning to the FX or UX chipbreaker sequences.
Q: Can the WNMG080404N-GZ insert be run completely dry without coolant?
A: Yes. In fact, running gray and ductile cast iron completely dry is highly recommended when utilizing the AC420K grade. The Super FF thick alumina (Al2O3) coating creates an exceptional thermal barrier layer. Introducing intermittent or poor flood coolant can induce thermal shocking, leading to microscopic crack propagation along the substrate matrix.
💡 Technical Grade Comparison & Troubleshooting Guide
Workpiece Material Matrix (ISO Classifications): Primary application falls within ISO K15 to K25 guidelines. Fully optimized for high-speed roughing of gray cast iron (FC200, FC250, FC300 / GG20, GG25, GG30) and nodular/ductile cast iron (FCD400, FCD500, FCD600 / GGG40, GGG50, GGG60) displaying abrasive surface crusts.
Machining Troubleshooting Guide: If rapid flank wear occurs, check that your surface cutting speed (vc) does not exceed structural limits for high-alloy castings, or transition to a harder K10-grade substrate matrix. If edge chipping or unexpected catastrophic pocket cracking appears, inspect structural clamping rigidity or reduce the feed rate (f) across interrupted areas to minimize sudden mechanical impact shocks.
Authorized Reference Documentation: Sizing geometries, mechanical pocket specifications, and dimensional tolerances fully comply with international ISO 1832:2017 standards for indexable cutting inserts. Performance envelopes are cross-verified using verified technical datasets published by Sumitomo Electric Hardmetal Corp.
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Technical FAQ & Buying Guide
When choosing CNC cutting tools, check the full model code, dimensions, grade and selected variant before ordering. Do not rely on the product image alone.
For carbide inserts, tool holders, drills and end mills, compare the mounting dimensions, connection type and manufacturer's specifications with your holder or machine. If you are unsure, share your existing part number and machining application with us before ordering.
Check the product listing for the selling unit, pack quantity and included components. If it is unclear whether the price is per piece or per pack, or whether a tool body and inserts are sold separately, contact us before purchasing.
Select cutting speed, feed rate and depth of cut using the relevant manufacturer's recommendations for your tool model, workpiece material, machine conditions and coolant method. The same settings are not suitable for every product or application.
Our automatic quantity discount is 6% off for 2–9 items and 12% off for 10 or more items, based on the total product quantity in the cart. Other offers may not combine with this discount; check the applicable offer conditions.
According to our shipping policy, orders are typically processed and shipped within 1–3 business days after confirmation. Delivery generally takes 5–20 business days, depending on your destination and shipping method. Customs clearance or unforeseen delays may affect delivery times. A tracking number is sent by email after shipment.