BEYOND S12M-STWCL09 Left Hand Internal Turning Tool Holder | 12mm CNC Boring Bar
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BEYOND S12M-STWCL09 Left-Hand Internal Turning Tool Holder – High-Rigidity 12mm CNC Boring Bar
1. Product Overview
"Which 12mm left-hand boring bar provides optimal chip clearance and rigidity for internal turning or sub-spindle profiling inside narrow blind holes down to a 16mm minimum bore?"
The BEYOND S12M-STWCL09 is an industrial-grade, left-handed steel-shank internal turning tool holder precisely engineered for small-diameter, high-accuracy lathe boring operations on sub-spindles or reverse tool configurations. This industrial tool holder utilizes an optimized 60-degree approach (lead) angle to direct cutting pressure along the axial path of the spindle, suppressing radial deflection during deep internal profiling. Specifically engineered for TCMT 0902 / TCGT 0902 indexable carbide inserts, it allows machinists to harness the full potential of positive rake chipbreaker geometries (such as HM for general medium machining or HQ for high-feed finish turning). This setup delivers superb chip fragmentation control, preventing long stringy nesting when processing sticky alloy steels, carbon steels, and stainless steel matrices inside narrow, confined chambers.
2. Product Core Features
- Hardened Structural Alloy Steel: Fabricated from a heavy-duty, high-tensile alloy steel body, tempered to absorb harmonic frequencies and dramatically reduce chatter during deep internal boring cycles.
- Ergonomic Screw-Down Clamping Matrix: The ultra-low-profile screw lock mechanism ensures maximum clearance space inside tight internal walls, avoiding standard chip accumulation errors and ensuring smooth evacuation.
- Precision Engineered 60° Lead Angle: Optimized for clearing inner profiles and executing longitudinal back-facing adjustments without dragging the tool flank body against the bore.
- Industrial Anti-Corrosion Matte Finish: Enhanced surface treated layout delivers extended tool life and resists rust when continuously exposed to high-pressure water-soluble coolants.
3. Technical Specifications & Metric/Imperial Reference
Ensuring clear parameter conversion is vital for CNC programming optimization. Below is the precise structural parsing of the S12M-STWCL09 standard international nomenclature rules:
| Parameter Dimension | Metric System Specification | Imperial Equivalent Measurement |
|---|---|---|
| Shank Diameter (d) | 12 mm | 0.4724 inches (Approx. 1/2") |
| Total Tool Length (L) | 150 mm | 5.9055 inches |
| Minimum Bore Diameter (D-min) | 16 mm | 0.6299 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 0.19 inches |
| Torx Key Driver Wrench Size | T6 / T7 | T6 / 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 - 210 m/min (360 - 688 SFM) | 0.02 - 0.12 mm/rev (0.0008 - 0.0047 IPR) |
| Stainless Steel Matrix (304, 316, 410) | 70 - 135 m/min (230 - 443 SFM) | 0.02 - 0.09 mm/rev (0.0008 - 0.0035 IPR) |
| Cast Iron Grades (GG20, GG25, GGG40) | 85 - 160 m/min (278 - 525 SFM) | 0.03 - 0.14 mm/rev (0.0012 - 0.0055 IPR) |
4. Product Application Scenarios
The specialized 12mm left-handed geometry of the S12M-STWCL09 tool holder makes it highly effective for rigid internal processing across diverse turning operations:
- Sub-Spindle Back Boring: Designed for seamless integration into multi-tasking CNC centers, Swiss-type automatic lathes, or dual-spindle setups requiring left-hand feed directions.
- Small-Bore Profiling & Pocketing: Perfect for machining narrow valve components, custom engine bushings, and small bearing bores where space is limited.
- Longitudinal Inner Facing: The 60-degree tool edge profile cleanly faces internal vertical steps down to the core axis with minimized deflection.
5. Compatibility & Equipment Interface
This 12mm round-shank boring bar fits directly into standard CNC lathe turret blocks, boring bar sleeves, split bushings, or Swiss-turn gang plates. It interfaces seamlessly with precision CNC lathe systems and automated turning setups from leading global brands (including Haas, Mazak, Citizen, Star, Tsugami, Doosan/DN Solutions, Mori Seiki, Okuma, and Fanuc). Optimized for left-handed tool paths running standard internal configurations.
6. BEYOND Premium Substrate & Grade Selection Matrix
To maximize chip control and wear life, pair your S12M-STWCL09 boring bar with the corresponding BEYOND proprietary insert grade tailored to your target material:
- BYM11 Grade (PVD Nano-Coated): Exceptional thermal shock resistance. Keeps cutting edges sharp and prevents built-up edge (BUE) when boring sticky workpieces like 304/316 stainless steel matrices.
- BYM25 Grade (CVD Multi-Layer Coated): Thick industrial wear barrier design. Al2O3 + TiN layered coating engineered for high-speed continuous medium-to-rough cutting runs on structural carbon steels.
- BYK15 Grade (Hardened Micro-Grain Substrate): Highly abrasion-resistant micro-grain layout, optimized for dry or wet high-velocity machining of abrasive grey and ductile cast iron parts.
7. Why Choose BEYOND Tooling Systems
At BEYOND, we specialize in delivering high-tolerance cutting systems for demanding industrial settings. Every S12M-STWCL09 holder passes strict Coordinate Measuring Machine (CMM) checking procedures to guarantee insert pocket dimensional accuracy within ±0.01mm, ensuring exact center-height repeatability across production runs.
Global Machinist Field Reports:
We run this left-hand bar on our dual-spindle lathe for secondary operations. Rigidity is excellent for a 12mm steel shank, and the pocket matches our TCMT09 inserts flawlessly.
Der Halter läuft bei uns täglich in der Kleinserienfertigung. Extrem präzise gearbeiteter Plattensitz, die Schraube klemmt absolut bündig. Späne fließen perfekt ab.
Perfect structural alignment inside our tight bores. Using the 9mm insert size gives extra clearance inside holes under 20mm. Very happy with the build quality.
複合加工機の背面主軸用に購入。12mmシャンクでも剛性がしっかりしており、内径ボーリング時のビビリがほぼ出ません。TCMT09チップのホールド感も非常に安定しています。
We swapped out expensive OEM holders for these BEYOND bars. Tolerances are exactly the same. Center-height is perfectly predictable after every index.
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.