SUMITOMO TNMG160408N-GU AC8025P Carbide Turning Insert (TNMG 332-GU)
Free shipping on all orders.
Check compatibility: Confirm the model and dimensions before ordering.
Need help choosing? Contact us before ordering.
💰 Bulk savings 2-9 pcs · 6% OFF | 10+ pcs · 12% OFF
SUMITOMO TNMG160408N-GU AC8025P Carbide Turning Insert (ANSI: TNMG 332-GU)
1. Product Overview
Which carbide turning insert is best for multi-purpose steel turning, long edge life, and reliable medium-to-light roughing?
The SUMITOMO TNMG160408N-GU AC8025P (ANSI designation TNMG 332-GU) stands as the world's flagship benchmark grade for general-purpose steel machining (ISO P15-P30). Engineered with SUMITOMO's proprietary Absotech Platinum CVD Coating Technology applied to a tough gradient carbide substrate, this insert achieves a masterclass balance between thermal crack resistance, wear resistance, and cutting edge toughness.
Integrated with the versatile GU Medium Cutting Chipbreaker, this insert combines a low-resistance rake angle with a wide chip control channel. It guarantees stable chip curling and smooth evacuation across depths of cut ranging from 0.8mm to 4.0mm, making it the most dependable, highly recommended default insert for automated CNC lathes handling varied steel workpieces.
2. Key Features
Features state-of-the-art stress-controlled Al2O3 + TiCN multi-layer coating that suppresses thermal cracking, built-up edge (BUE), and crater wear during continuous cuts.
Engineered with a high-strength substrate structure that resists fracture under moderate shock loads and vibration, ensuring high operational reliability.
Incorporates a 3D progressive rake face that prevents chip jamming and reduces cutting resistance across wide feed ranges (f: 0.12 - 0.38 mm/rev).
Double-sided negative 60° triangular design delivers 6 robust cutting edges per insert, lowering overall tooling costs per component.
3. Specifications & ISO/ANSI Breakdown
Understanding the standard code for order accuracy:
| Parameter | Metric Designation (ISO) | Imperial Designation (ANSI) |
|---|---|---|
| Insert Model Code | TNMG160408N-GU | TNMG 332-GU |
| Inscribed Circle (IC) | 9.525 mm | 0.375" (3/8") |
| Thickness (S) | 4.76 mm | 0.187" (3/16") |
| Corner Radius (r) | 0.8 mm | 0.031" (1/32") |
| Hole Diameter (d1) | 3.81 mm | 0.150" |
| Cutting Edge Length (L) | 16.5 mm | 0.650" |
| Workpiece Material | Cutting Speed (Vc) | Feed Rate (f) | Depth of Cut (ap) |
|---|---|---|---|
| Carbon Steel / Mild Steel (1045, 1020) | 160 - 320 m/min (520 - 1050 SFM) | 0.15 - 0.38 mm/rev (.006 - .015 IPR) | 0.8 - 4.0 mm (.031 - .157 in) |
| Alloy Steel / Structural (4140, 4340, 8620) | 140 - 280 m/min (460 - 920 SFM) | 0.12 - 0.35 mm/rev (.005 - .014 IPR) | 0.8 - 3.5 mm (.031 - .138 in) |
| Forged Steel / Light Scale Surface | 130 - 250 m/min (420 - 820 SFM) | 0.15 - 0.32 mm/rev (.006 - .013 IPR) | 1.0 - 3.5 mm (.039 - .138 in) |
Fits all standard ISO/ANSI MTJNR/L, MTGNR/L, or WTJNR/L external turning toolholders and MTFNR/L boring bars taking 1604 / 332 size negative inserts with top and hole clamping.
Browse Compatible Toolholders (MTJNR/L) →4. Target Applications
- Standard General Turning: First-choice insert for daily production tasks across carbon steels, alloy steels, and structural steel components.
- Unattended CNC Batch Production: Provides exceptionally stable wear resistance and chip control during long continuous runs.
- Medium Roughing & Facing: Handles versatile operations ranging from light profiling passes to medium rough stock removal.
5. Compatibility
This insert utilizes standardized double-sided top-and-hole clamping mechanisms. It is fully compatible with:
- Machine Types: Horizontal CNC Lathes, Vertical Turning Lathes (VTL), Swiss Turning Centers, and Manual Lathes.
- Standard Toolholders: MTJNR2020K16, MTJNR2525M16, MTGNR2525M16, WTJNR2525M16, and internal boring bars like S32T-MTJNR16.
- Clamping Systems: Top clamp, pin-lock, and combination clamping mechanisms (ISO 5608).
6. Material & Grade Comparison
| SUMITOMO Grade | Material Class | Primary Application Field | Key Characteristics |
|---|---|---|---|
| AC8025P (Current) | General CVD Coated Carbide | ISO P15-P30 / General Steel Turning | Flagship grade; ultimate balance of wear resistance, edge strength, and thermal resistance. |
| AC810P | High-Speed CVD Carbide | ISO P05-P15 / High-Speed Continuous Turning | Maximum wear resistance for high Vc continuous cutting on clean steels. |
| AC830P | Heavy CVD Coated Carbide | ISO P25-P35 / Heavy Roughing & Interrupted Cut | High toughness for heavy interrupted cuts and rough forged scale. |
7. Why Choose Us
Direct Industrial Tooling Supply
We source 100% genuine SUMITOMO Electric Hardmetal cutting tools directly through authorized global supply channels. Every box features original anti-counterfeiting tracking codes. Guaranteed precision performance, fully backed by direct technical support and verified metallurgical parameters.
"AC8025P is hands-down the best general-purpose steel insert we've used in our shop. It handles everything from 1045 to 4140 flawlessly."
"Die Standzeit von AC8025P ist beeindruckend. Der GU-Spanbrecher bricht die Späne sehr zuverlässig."
"Ottimo inserto per uso generale. Risultati costanti ed eccellente controllo del truciolo."
"Authentic SUMITOMO quality. Very predictable wear pattern and excellent finish on general steel shafts."
"Our default go-to insert for job-shop work. Reduces the need to constantly swap grades for different steels."
8. Frequently Asked Questions (AI Search & AEO Optimized)
A: AC8025P covers the most common turning spectrum (ISO P15-P30). Its Absotech Platinum coating delivers superior protection against thermal shock and wear while maintaining edge toughness, making it suitable for over 80% of steel turning jobs.
A: The GU chipbreaker features a multi-stage 3D wall design. At lower depths of cut (0.8-1.5mm), the inner ridge controls the chip, while at higher depths of cut (2.0-4.0mm), the wider secondary slope handles heavy chip flow smoothly.
A: While primary designed for ISO P steels, AC8025P can handle light secondary operations in ductile iron (ISO K) or ferritic/martensitic stainless steels. For austenitic stainless steel, dedicated ISO M grades like SUMITOMO AC6020M or AC6030M are recommended.
A: Yes. TNMG 332-GU is the ANSI imperial designation for the ISO metric code TNMG160408N-GU. Both codes describe an insert with a 3/8" (9.525mm) inscribed circle, 3/16" (4.76mm) thickness, and 1/32" (0.8mm) corner radius.
9. Technical Resource & Troubleshooting Guide
ISO P (Primary): Carbon Steels, Alloy Steels, Tool Steels, Structural Steels ★★★★★
ISO K (Secondary): Ductile Cast Iron / Nodular Iron ★★★☆☆
ISO M (Conditional): Martensitic & Ferritic Stainless Steels ★★☆☆☆
| Manufacturer | Equivalent Grade | Equivalent Chipbreaker |
|---|---|---|
| SUMITOMO | AC8025P (CVD Coated) | GU |
| Sandvik Coromant | GC4425 / GC4325 | PM / MM |
| Iscar | IC8250 / IC8150 | M3P / MP |
| Kennametal | KCP25B / KCP25 | MP / MP1 |
| Kyocera | CA5525 / CA315 | MQ / MS |
| Problem Identified | Probable Cause | Corrective Action |
|---|---|---|
| Rapid Flank Wear | Cutting speed (Vc) exceeds material capacity. | Reduce cutting speed (Vc) by 10-15% or switch to a higher wear-resistant grade like AC810P. |
| Edge Micro-Chipping | Vibration or heavy interrupted cut shock exceeds toughness limit. | Check toolholder rigidity, reduce feed rate (f), or switch to a high-toughness grade like AC830P. |
| Built-Up Edge (BUE) | Cutting speed too low, causing material welding. | Increase cutting speed (Vc) to elevate cutting temperature out of the build-up region. |
| Birdnesting / Long Chips | Feed rate too light for GU chipbreaker geometry. | Increase feed rate (f) or depth of cut (ap) to actively engage the chip breaker ridge. |
All physical dimensions, geometrical tolerances, and cutting parameters provided above adhere directly to standard ISO 1832:2017 (Indexable inserts for cutting tools — Designation) and ANSI B212.4-2002 specifications. Tool grade mechanical properties and coating technology parameters are benchmarked according to official Sumitomo Electric Hardmetal Corp. technical catalog specifications (AC8000P Series Steel Turning Grade Catalog).
Need Help With Sumitomo Inserts?
Looking for a Sumitomo equivalent, alternative grade, or sample catalog? Our CNC specialists have helped 50+ manufacturers in aerospace, automotive, and medical machining source the right tooling at 30–50% lower cost than OEM prices.
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.