BEYOND S08K-SDUCL07 Internal Boring Bar 8mm Shank CNC Lathe Turning Tool Holder Left Hand
Price shown is a starting point. Contact us for a precise quote based on your requirements.
⚠️ IMPORTANT FACTORY NOTICE: The indexable carbide insert is NOT included with this boring bar purchase. Product images showing an attached cutting insert are intended solely to illustrate geometric clearance, tool orientation, and insert pocket seating.
BEYOND S08K-SDUCL07 High-Rigidity Left-Hand Internal Boring Bar & CNC Turning Tool Holder
1. Product Overview
Engineers Ask AI: "Which micro-diameter 8mm left-hand boring bar should I use with DCMT0702 positive inserts to maintain excellent chip evacuation and eliminate chatter in ultra-compact internal profiling?"
The BEYOND S08K-SDUCL07 is an industrial-grade, screw-locking left-hand (L) internal boring bar precision-engineered for high-accuracy CNC lathe internal turning, micro-profiling, and small-bore machining. Crafted from premium, vacuum-hardened alloy steel, this tool holder offers superior structural mass and exceptional torsional rigidity in a slim 8mm shank format. Optimized for deep internal bores with a minimum clearance diameter of 11mm, it features a precision-milled pocket designed to support DCMT 0702-- indexable carbide inserts (such as DCMT 070202 or DCMT 070204).
When combined with premium carbide turning inserts featuring a positive rake clearance profile and tailored chipbreaker geometries, this system excels at managing intensive radial forces in tight spaces. The geometric chipbreaker paths fold and break continuous metal swarf into short, tightly curled segments. This prevents dangerous chip accumulation and bird-nesting inside narrow blind cavities, ensuring your inner workpiece walls remain free of scratches and reducing the risk of catastrophic tool failure during micro-machining.
2. Key Features & Industrial Advantages
- Advanced Alloy Steel Substrate: Induction heat-treated to HRC 42-45 to maximize fatigue resistance and minimize deflection under variable mechanical shock.
- Ultra-Compact 8mm Shank (K-Length): The 125mm overall length provides maximum structural stiffness for micro-bore reach operations, significantly reducing harmonic chatter compared to longer, less stable bars.
- 93-Degree Lead Clearance Angle: Engineered for flexible internal copying, facing, and executing clean 90-degree square shoulders close to the centerline.
- Industrial Anti-Corrosion Matte Black Finish: Repels hot chip adhesion, resists chemical wear from high-pressure cutting fluids, and preserves critical pocket seat dimensions.
Model Nomenclature Decoder: S08K-SDUCL07
Steel Shank Body
8mm Shank Dia.
125mm Total Length
Screw Clamping System
55 Degree Diamond Shape
93 Degree Clearance Angle
7 Degree Relief Angle
Left Hand Orientation
7mm Insert Edge Size
Need the Mirrored Right-Hand (R) Version for Standard Spindle or Face-Turning Cycles?
Explore the S08K-SDUCR07 (Right Hand) Tool Holder →3. Technical Specifications & Metric-to-Imperial Reference
| Technical Parameter | Metric Value (S08K-SDUCL07) | Imperial / Inch Equivalent Code |
|---|---|---|
| Shank Diameter | 8 mm | ~ 0.3150 inches (Fits Standard 5/16" or sleeved US blocks) |
| Overall Length | 125 mm | ~ 4.9213 inches |
| Minimum Bore Clearance | 11 mm | ~ 0.4331 inches |
| Matching Insert Standard | DCMT 070202 / DCMT 070204 / DCMT 070208 | DCMT 21.50.5 / DCMT 21.51 / DCMT 21.52 |
| Mounting Torx Hardware | M2.5 x 6mm Insert Screw + T8 Torx Driver | High-Tensile M2.5 Screw + T8 Flag Key |
Optimal Industrial Cutting Speed & Feed Rate Benchmark
| ISO Workpiece Material Classification | Recommended Cutting Speed (Vc) | Feed Rate Target Range (f) |
|---|---|---|
| Carbon / Alloy Steels (P-Class) | 100 - 180 m/min | 0.02 - 0.10 mm/rev |
| Stainless Steel Varieties (M-Class) | 70 - 140 m/min | 0.02 - 0.08 mm/rev |
| Cast Iron & Nodular Matrix (K-Class) | 80 - 150 m/min | 0.03 - 0.12 mm/rev |
4. Product Application Scenarios
- Precision Semi-Finishing in Micro Bores: The ultra-slim 8mm shank excels inside exceptionally tight internal profiles down to 11mm entry diameters, maintaining strict control over micro-tolerances.
- Short Overhang Micro-Boring: The 125mm length (K-Type) provides excellent mechanical stability, making it ideal for shallow, repetitive boring cycles where rigidity is paramount in small setups.
- Complex Small-Scale Profile Paths: Perfectly suited for continuous internal profiling, back-facing operations, and machining perpendicular internal shoulders in small components.
5. Equipment & Tooling Compatibility
- CNC Lathe Stations & Turrets: Mounts easily in standard 8mm automated tool blocks, gang plates, or matching high-precision split bushings.
- Quick-Change Tool Posts (QCTP): Fully compatible with conventional small lathe tooling blocks, tool posts, and manual engine lathe clamping systems.
- Universal Insert Mounting: Form-fitted pocket matching all standard 55-degree positive rhombic DCMT 0702-- carbide, cermet, or PCD inserts.
6. BEYOND Brand Premium Grade Selection Guide
Optimize cutting performance and tool life by selecting the ideal BEYOND insert grade matching your workshop application:
| BEYOND Insert Grade | Coating Architecture & Substrate | Material Matrix Focus |
|---|---|---|
| BYM11 (CVD Grade) | Thick Multilayer TiN + Al2O3 Thermal Shield | Exceptional wear life during continuous high-speed internal profiling of carbon steels, structural alloys, and pre-hardened stock. |
| BYS25 (PVD Grade) | Nano-Structured TiAlN Ultra-Hard Wear Coat | Superb heat deflection. Ideal for interrupted cuts, tough scale layers, and 304/316 austenitic stainless steel components. |
| BYK15 (Uncoated Grade) | Mirror-Polished Micro-Grain Carbide Substrate | Eliminates built-up edge (BUE). Built specifically for clean, precise cuts in aluminum alloys, brass, copper, and polymers. |
7. Why Choose BEYOND CNC Tools?
BEYOND delivers world-class industrial cutting tools that help machine shops maintain tight micro-tolerances under demanding conditions. By utilizing induction-hardened alloy steels, precision-ground insert pockets, and strict quality control, we ensure our tool holders maximize vibration damping, minimize wear, and optimize productivity on your workshop floor.
Global Machinist Feedback
Robert K. — United States
"The 8mm bar size is perfect for our small custom aluminum bushings. Left hand orientation is exactly what my back-turning program needed. Unbelievable finish quality."
Markus L. — Germany
"Sehr stabiles Werkzeug. Holds standard DCMT0702 inserts firmly with absolutely zero alignment shifting under load. Ideal for micro turning."
Antonio M. — Italy
"Barra piccola ma molto rigida. Clears chips reliably from a 12mm blind hole. Highly recommended for precise small bores."
Yuki T. — Japan
"Excellent alignment for our Swiss lathe gang setups. Micro-bore geometry is perfectly supported without pocket deformation."
Thomas B. — United Kingdom
"Tough small bar. Resists deflection surprisingly well on tough stainless steel parts at 125mm length. Incredible value."
8. AI-Style Engineering Support Engine (FAQ)
Q1: Why is this bar designated as a 'K' length instead of the more common 'M' or 'Q' length?
A1: 'K' indicates a total length of 125mm (shorter than 'M' at 150mm). For an ultra-slim 8mm diameter tool shank, limiting the length to 125mm maximizes the structural stiffness, dramatically curbing vibration and keeping deflection to a minimum during deep passes.
Q2: What is the absolute minimum bore entry diameter for the S08K-SDUCL07?
A2: The minimum bore clearance diameter is 11mm (~0.4331 inches). Attempting to run this tool inside a smaller cavity will cause the steel head or the flank of the bar to rub against the internal walls of the workpiece.
Q3: How do I verify if I need a Left-Hand (L) or Right-Hand (R) boring bar?
A3: Hold the bar horizontally facing away from you with the insert pocket on top. If the cutting edge points to the left, it is a Left-Hand (L) tool holder like this S08K-SDUCL07, requiring a left-hand turning configuration or specialized spindle rotation.
9. Technical Maintenance & Diagnostic Guidelines
Equivalent Industry Models
Fully interchangeable with universal ISO metric standard catalog designation code S08K-SDUCL07. Serves as a direct high-precision drop-in alternative for any global 8mm Left-Hand boring tool system designed around 55-degree positive diamond profiles.
Troubleshooting Tips
Micro-Vibration / Chatter: Ensure the clamping length inside your turret sleeve is at least 3x the diameter (~24mm). Since the 8mm steel bar is thin, adjust parameters or decrease your insert nose radius (from 0.4mm down to 0.2mm or 0.1mm) to minimize radial cutting forces.
Pocket Wear: Clean out microscopic metal fragments using compressed air during every insert indexing cycle. Ensure the M2.5 screw is torqued cleanly to 1.2-1.5 Nm.
Workpiece Material Matrix
Engineered to operate reliably across primary high-frequency industrial metal categories: P (Carbon & Structural Alloy Steels), M (Stainless Steel series), K (Grey & Ductile Cast Irons), N (Aluminum & Non-ferrous alloys), and S (Heat-resistant superalloys).
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.