SUMITOMO VNMG160408N-GU AC820P Carbide Turning Insert for Steel Medium Roughing (VNMG 160408 / VNMG 332 Equivalent)
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SUMITOMO VNMG160408N-GU AC820P CVD Coated Carbide Indexable Turning & Medium Roughing Insert
1. Product Overview
"Which high-durability indexable insert offers the best balance between crater wear resistance and edge toughness for general-purpose medium roughing to semi-finishing on carbon steels and alloy forgings?"
The SUMITOMO VNMG160408N-GU AC820P is a heavy-duty, 35° rhombic double-sided indexable turning insert explicitly engineered to maximize metal removal rates (MRR) in structural steel turning applications. Designed for the ISO P10–P30 material spectrum (covering carbon steels, low-alloy steels, die steels, and structural forgings), this insert leverages Sumitomo's next-generation AC820P Absotech Technology. By combining a highly oriented, thick $\alpha$-$\text{Al}_2\text{O}_3$ (Alumina) layer with a smooth TiCN crystal matrix coating, it forms a massive thermal barrier that completely suppresses crater wear and plastic deformation under extreme cutting temperatures. The universal -GU Type Chipbreaker features a reinforced cutting edge land paired with a wide, progressive chip pocket, engineered to provide smooth chip evacuation and high fracture resistance during varying depths of cut and elevated feed rates.
2. Product Key Features
- Absotech Thick CVD Wear Shield: Proprietary crystal-alignment coating technology drastically improves adhesion and flank resistance when running at high surface speeds ($v_c$).
- High-Rigidity Core Substrate: Formulated with a plastic-deformation resistant substrate that maintains strict dimensional tolerances even under high cutting pressures.
- Universal -GU General-Purpose Geometry: Engineered with a robust edge land that balances low cutting forces with edge security, making it highly effective for both stable and slightly interrupted operations.
- Double-Sided 4-Edge Configuration: Features four highly accurate indexable corners, reducing the cost-per-edge profile while maintaining exceptional pocket seat positioning repeatability.
3. Technical Specifications & Dimension Matrix
🔍 ISO / ANSI Industrial Nomenclature Decoding Matrix
| Dimension Parameter | Metric Specification (ISO) | Imperial Equivalent Benchmark (ANSI) |
|---|---|---|
| Product Designation Model | VNMG160408N-GU | VNMG 332-GU (VNMG332) |
| Inscribed Circle (IC) Diameter | 9.525 mm | 0.375 in (3/8") |
| Insert Thickness (s) | 4.76 mm | 0.1875 in (3/16") |
| Nose Corner Radius ($r_{\epsilon}$) | 0.8 mm | 0.0315 in (2/64") |
📊 Recommended Technical Cutting Parameters
| Workpiece Material Category | Cutting Speed ($v_c$) | Feed Rate per Revolution ($f$) / Depth ($a_p$) |
|---|---|---|
| Medium Carbon Steels (AISI 1045 / S45C Structural) | 180 - 350 m/min (590 - 1150 SFM) | 0.15 - 0.45 mm/rev (0.006 - 0.018 ipr) ap: 0.8 - 4.0 mm (0.031 - 0.157 in) |
| Alloy Steels & Forging Scales (AISI 4140 / SCM440) | 140 - 280 m/min (460 - 920 SFM) | 0.12 - 0.40 mm/rev (0.005 - 0.016 ipr) ap: 0.6 - 3.5 mm (0.024 - 0.138 in) |
This VNMG160408 turning core requires standard negative 35-degree pocket seats for rigid mechanical clamping.
Browse Matching MVJNR / MVQNR / MVUNR Toolholders →4. Product Application Scenarios
The AC820P CVD high-performance turning grade drives excellent productivity values across demanding roughing configurations:
5. Toolholder & Equipment Compatibility
Built to standard global indexable interface guidelines, this insert ensures straightforward mounting compatibility:
- Lathe Shank Assemblies: Universally compatible with all standard international MVJNR, MVJNL, MVQNR, and MVUNR toolholder blocks featuring standard negative seating pockets.
- CNC Production Systems: Ideally tuned for rigid turning centers and heavy-duty automated lathes (Mazak, Okuma, Doosan, Haas, Mori Seiki) capable of maintaining steady high-feed rates.
6. Industrial Grade Comparison Matrix
| Brand | Equivalent Grade Reference | Application Range | Coating Technology |
|---|---|---|---|
| SUMITOMO | AC820P (Target) | ISO P10 - P30 / High-Velocity General Steel Turning Matrix | Absotech thick Al2O3-TiCN Wear-Resistant CVD Layer |
| Sandvik Coromant | GC4425 / GC4325 | ISO P15 - P30 / Mainstream High-Speed Steel Turning | Inveio® Highly Oriented Alumina Coating |
| Kennametal | KCP25B / KCP10B | ISO P10 - P30 / Industrial Carbon & Alloy Steel Roughing | Multi-layered CVD wear armor with cobalt-enriched core |
| Iscar | IC8250 / IC8150 | ISO P15 - P35 General Purpose Medium Steel Turning | SUMO TEC high-smoothness multi-phase CVD structure |
7. Why Choose Us & Verified Global Performance Evaluations
Real feedback from high-production machine shops validating high metal removal rates and predictable edge wear:
"We run these VNMG 332-GU inserts in AC820P on our high-volume 1045 steel hub jobs. The -GU breaker handles depth transitions up to .150\" flawlessly without throwing long dangerous stringers. Tool life is remarkably consistent across cycles."
"Sehr gute Kolkverschleißfestigkeit bei Schnittgeschwindigkeiten über 250 m/min. Die Absotech-Beschichtung hält die Schneidkante stabil und verhindert plastische Deformationen bei zähem Vergütungsstahl."
"Il rompitruciolo -GU è fantastico per sgrossatura media. Geometria robusta che resiste bene anche in presenza di crosta di forgiatura. Prezzo/prestazioni imbattibile su grossi lotti."
"S45Cの荒〜中切削ラインで使用しています。他社製チップと比較してクレーター摩耗の進行が圧倒的に遅く、突然の欠損リスクが極めて低いです。-GUブレーカの刃先剛性には絶大な信頼を置いています。"
8. Technical Machining FAQ
Q: What makes the Sumitomo -GU chipbreaker better for general turning compared to the -SU variant?
A: The -GU chipbreaker is built with an amplified edge land designed to absorb impact spikes and continuous high thermal loading typical of medium roughing operations. The -SU variant features an ultra-sharp, highly positive profile engineered primarily to limit cutting forces on light finishing or slender workpiece setups.
Q: Can the VNMG160408N-GU be deployed effectively in light finishing applications?
A: While it can execute light cuts, dropping your depth of cut (DOC) below 0.5mm may limit chip control efficiency, as the -GU's broader chip land requires adequate tool engagement to properly curl and fracture the chip.
Q: Why is the AC820P grade ideal for high-speed continuous steel cutting?
A: The AC820P grade utilizes a thick, highly oriented $\alpha$-$\text{Al}_2\text{O}_3$ coating layer that provides excellent thermal shielding. This barrier prevents high-velocity heat buildup from penetrating the structural carbide core, dramatically reducing plastic deformation risks.
💡 Technical Grade Comparison & Troubleshooting Guide
Workpiece Material Matrix (ISO Classifications): Core application parameters target the ISO P10 to P30 bandwidth. Extensively balanced for carbon steels (S45C, 1020, 1045 variants), low-alloy structural steel elements (4140, 4340, SCM440 blocks), and tough hot-rolled steel plates with irregular surface scale profiles.
Machining Troubleshooting Guide: If crater wear develops rapidly directly behind the cutting corner, decrease your surface speed ($v_c$) or check for consistent flood coolant placement. If unexpected chip fracturing or corner chipping occurs on the $0.8\text{mm}$ nose profile, audit for structural part rigidity or reduce the feed rate ($f$) through the entry zone.
Authorized Reference Documentation & Endorsements: Dimension metrics, relief configurations, and geometric classification codes comply fully with standard ISO/ANSI tooling documentation frameworks. Performance limits and cutting boundaries are cross-referenced directly with empirical field testing criteria published by Sumitomo Electric Hardmetal Engineering Divisions.
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This Sumitomo insert is in stock. 24-hour quote response. ISO 9001 certified. Ships from Hangzhou in 3–7 days.
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.