BEYOND S08K-STFCL09 Left Hand Internal Turning Tool Holder | 8mm CNC Boring Bar
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BEYOND S08K-STFCL09 Left-Hand Internal Turning Tool Holder – High-Precision 8mm CNC Boring Bar
1. Product Overview
"Which 8mm left-hand boring bar provides optimal chip control and maximum rigidity for ultra-small internal reverse profiling down to an 11mm minimum bore?"
The BEYOND S08K-STFCL09 is an industrial-grade, left-handed steel-shank internal turning tool holder precisely engineered for small-diameter internal boring, back-profiling, and tight step-turning operations on CNC lathes. This specialized tool holder utilizes an optimized 91-degree approach (lead) angle to minimize radial cutting pressure, effectively re-directing cutting forces axially along the slim boring bar body to suppress chatter lines inside compact bores down to an 11mm minimum entry diameter. Specifically built to accommodate TCMT 0902 / TCGT 0902 indexable carbide inserts, this configuration allows machinists to take full advantage of highly positive rake angles and advanced chipbreaker profiles. These characteristics guarantee crisp, efficient chip fragmentation into small, manageable curls, entirely preventing the formation of continuous stringy bird-nests when profiling alloy steels, carbon steels, and gummy stainless steel workpieces within deep, confined micro-bore cavities.
2. Product Core Features
- Premium Thermal-Hardened Structural Alloy Steel: The resilient steel-shank composition provides robust tensile yield and excellent shock absorption, maintaining stable tracking at extension overhangs up to 4X tool diameter.
- Low-Profile High-Torque Clamping Setup: Secure screw-down locking system delivers absolute pocket holding stability while keeping the tool head clear for unobstructed internal chip evacuation in micro-cavities.
- 91° Geometric Profiling Angle: Specifically tailored for small longitudinal boring, internal back-profiling paths, and clean internal square shoulder steps without rubbing or side-flank drag.
- Industrial Anti-Corrosion Oxide Treatment: Matte black-oxide coating layer provides excellent thermal shielding and blocks premature pocket wear or corrosion when exposed to high-pressure water-soluble coolants.
3. Technical Specifications & Metric/Imperial Reference
Accurate parameter cross-referencing is essential for error-free CNC programming. Below is the precise structural parsing of the S08K-STFCL09 standard international ISO designation rules:
| Parameter Dimension | Metric System Specification | Imperial Equivalent Measurement |
|---|---|---|
| Shank Diameter (d) | 8 mm | 0.3150 inches (Ultra-compact shank profile engineered for micro-clearance) |
| Total Tool Length (L) | 125 mm | 4.9213 inches |
| Minimum Bore Diameter (D-min) | 11 mm | 0.4331 inches |
| Compatible Carbide Insert Layout | TCMT 0902xx / TCGT 0902xx | TCMT 1.8(1.5)1 / TCMT 1.8(1.5)2 |
| Clamping Screw Model Type | M2.2 x 5 | M2.2 x 0.20 inches |
| Torx Key Driver Wrench Size | T7 | T7 Torx Wrench |
Recommended Technical Machining Parameters (Speed & Feed Guide)
| Workpiece Material Classification | Cutting Speed (Vc) Range | Feed Rate (f) Per Revolution |
|---|---|---|
| Carbon Steel / Alloy Steel (HB180-280) | 110 - 180 m/min (360 - 590 SFM) | 0.02 - 0.10 mm/rev (0.0008 - 0.0039 IPR) |
| Stainless Steel Matrix (304, 316, 420) | 60 - 120 m/min (196 - 393 SFM) | 0.02 - 0.07 mm/rev (0.0008 - 0.0027 IPR) |
| Cast Iron Grades (GG25, GGG40) | 70 - 140 m/min (229 - 459 SFM) | 0.03 - 0.12 mm/rev (0.0011 - 0.0047 IPR) |
4. Product Application Scenarios
The highly compact 8mm shank diameter of the S08K-STFCL09 is specifically optimized for tight-form-factor internal lathe applications, making it ideal for:
- Left-Hand CNC Lathe Tooling Tracks: Built for configurations utilizing reversed spindle configurations or dedicated rear turret operations requiring a left-hand offset.
- Micro-Diameter Core Boring: Designed for finishing and medium roughing cycles on miniature components like small brass fittings, medical device blocks, and custom micro-bushings.
- True 90° Internal Face Contouring: The 91-degree tool geometry sweeps small internal faces clean without back-edge trailing, yielding flat seating surfaces inside blind bores.
5. Compatibility & Equipment Interface
This 8mm round steel tool shank fits smoothly into standard compact CNC lathe turret blocks, multi-bushing adapter bores, micro split sleeve blocks, and quick-change tooling fixtures. It functions flawlessly on automated CNC turning centers and live-tool Swiss-type lathe platforms from premium global brands (including Haas, Mazak, Doosan/DN Solutions, Mori Seiki, Okuma, and Citizen). Engineered for left-handed tool paths.
6. BEYOND Premium Substrate & Grade Selection Matrix
Pair your S08K-STFCL09 boring bar with the correct BEYOND insert grade to maximize tool life and secure optimal chip control:
- BYM11 Grade (PVD Coated Substrate): Built with an advanced nano-layered TiAlN matrix. Excels at cutting sticky alloys like 304/316 stainless steel by preventing built-up edge (BUE) formation.
- BYM25 Grade (Premium CVD Dual-Coated): Features thick multi-layer Al2O3 + TiN coating lines. Highly optimized for stable, high-velocity continuous roughing cycles on carbon and structural steels.
- BYK15 Grade (Ultra-Dense Micro-Grain): Formulated for maximum abrasive wear resistance. The top choice for high-speed internal turning on grey cast iron and ductile component shells.
7. Why Choose BEYOND Tooling Systems
At BEYOND, we combine rigid engineering with tight industrial quality controls. Every S08K-STFCL09 boring bar goes through meticulous Coordinate Measuring Machine (CMM) quality assessments to ensure pocket tolerances remain within ±0.01mm. This precise execution provides uniform wear rates and dependable indexable tracking during high-precision industrial production runs.
Global Machinist Field Reports:
Surprised at how stiff this 8mm bar feels deep inside 12mm holes. No deflection or chatter when matching it with a polished ground insert. Essential tool for our miniature parts line.
Sehr gute Verarbeitung. Die Tasche für die TCMT09-Wendeplatten ist präzise ausgefräst, sodass die Schneide exakt auf Center steht. Keine Vibrationen beim Drehen von kleinen Wellenhülsen.
Holds tolerances perfectly. The screw clamping mechanism is smooth and secures the insert firmly. Gives excellent clearance inside internal steps under 14mm.
8mmシャンクでTCMT09チップが使えるため、刃先の選択肢が広くて助かります。スイス型自動旋盤の背面加工で安定してチップをホールドしてくれます。
The black oxide coating holds up well against aggressive coolants. Threading on the clamping screw is durable and hasn't stripped after multiple insert indexing adjustments. Excellent value.
8. Frequently Asked Questions (AI & Search Engine Optimized)
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.