BEYOND S16Q-STFCL16 Left Hand Internal Turning Tool Holder | 16mm CNC Boring Bar
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BEYOND S16Q-STFCL16 Left-Hand Internal Turning Tool Holder – High-Rigidity 16mm CNC Boring Bar
1. Product Overview
"Which 16mm left-hand boring bar provides optimal chip clearance and high rigidity for reverse internal turning or back-boring inside narrow cavities down to a 20mm minimum bore?"
The BEYOND S16Q-STFCL16 is an industrial-grade, left-handed steel-shank internal turning tool holder precisely engineered for medium internal boring, profiling, and step-turning operations on CNC lathes. This industrial tool holder utilizes an optimized 91-degree approach (lead) angle to minimize radial cutting pressure, effectively re-directing cutting forces axially along the lathe spindle line to eliminate harmful chatter spikes in deep cavities down to a 20mm minimum bore entry. Specifically engineered for TCMT 16T3 / TCGT 16T3 indexable carbide inserts, it allows machinists to exploit premium positive rake chipbreaker geometries (such as HF for finishing or HM/HM2 for medium-to-rough cutting). This setup guarantees superior chip fragmentation, successfully breaking up potential stringy nests when processing sticky alloy steels, hardened carbon steels, and stainless steel matrices inside deep, constrained internal chambers.
2. Product Core Features
- High-Tensile Hardened Alloy Steel: Fabricated from an ultra-tough structural spring-steel matrix, thermal-hardened to optimize tensile strength and suppress harmonics at reach lengths up to 4X shank diameter.
- High-Torque Screw-Down Clamping Matrix: Secure low-profile screw-lock setup offers maximum clearance for heavy chip volume evacuation, preventing pocket erosion and insert shifts under high feed velocities.
- 91° Precision Clearance Profile: Tailored for deep boring, longitudinal profile steps, and left-handed counter-directional contouring paths without risk of tool body dragging or flank-wear rubbing.
- Industrial Anti-Wear Oxide Finish: Advanced black-oxide skin layer maximizes resistance to thermal scaling and corrosion when continuously exposed to high-pressure water-soluble cutting oils.
3. Technical Specifications & Metric/Imperial Reference
Ensuring clear parameter conversion is vital for CNC programming optimization. Below is the precise structural parsing of the S16Q-STFCL16 standard international nomenclature rules:
| Parameter Dimension | Metric System Specification | Imperial Equivalent Measurement |
|---|---|---|
| Shank Diameter (d) | 16 mm | 0.6299 inches (5/8" Equivalent) |
| Total Tool Length (L) | 180 mm | 7.0866 inches |
| Minimum Bore Diameter (D-min) | 20 mm | 0.7874 inches |
| Compatible Carbide Insert Layout | TCMT 16T3xx / TCGT 16T3xx | TCMT 3(2.5)1 / TCMT 3(2.5)2 |
| Clamping Screw Model Type | M4.0 x 10 | M4.0 x 0.39 inches |
| Torx Key Driver Wrench Size | T15 | T15 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) | 130 - 210 m/min (426 - 689 SFM) | 0.08 - 0.25 mm/rev (0.0031 - 0.0098 IPR) |
| Stainless Steel Matrix (304, 316, 410) | 80 - 150 m/min (262 - 492 SFM) | 0.06 - 0.20 mm/rev (0.0023 - 0.0078 IPR) |
| Cast Iron Grades (GG20, GG25, GGG40) | 90 - 170 m/min (295 - 557 SFM) | 0.08 - 0.30 mm/rev (0.0031 - 0.0118 IPR) |
4. Product Application Scenarios
The highly rigid 16mm left-handed core of the S16Q-STFCL16 tool holder makes it an excellent choice for a variety of critical internal turning jobs:
- Left-Hand CNC Lathe Operations: Tailor-made for lathes utilizing reverse spindle rotations or specific turret configurations requiring left-hand tool tracking.
- Precision Back-Boring & Profiling: Delivers exceptional support for back-boring steps and internal profiling maneuvers where tool access from the rear wall is mandatory.
- Longitudinal Step-Boring: The 91-degree lead configuration allows seamless pocket-turning transitions down internal right-angle walls with near-zero radial stress or push-off.
5. Compatibility & Equipment Interface
This 16mm round-shank boring bar fits directly into standard CNC lathe turret blocks, boring bar sleeve blocks, split bushings, or specialized tool holders. It interfaces seamlessly with precision CNC lathe systems and automated turning setups from leading global brands (including Haas, Mazak, Doosan/DN Solutions, Mori Seiki, Okuma, Citizen, 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 S16Q-STFCL16 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 S16Q-STFCL16 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:
Hard to find high-quality 16mm left-handed boring bars for our reverse spindle setups. This BEYOND holder holds the TCMT16 insert perfectly flat. Rigid, zero chatter, highly recommended.
Der Linksdrehmeißel S16Q-STFCL16 ist absolut maßhaltig gefertigt. Wir nutzen ihn für spezielle Innenkonturen auf unserer Mazak. Formstabilität und Spanabfuhr sind tadellos.
Highly rigid steel construction. The 16mm left-hand shank profile is exactly what we needed for clearing internal channels under 22mm diameter. No flexing issues found.
逆転切削や背面加工用に購入。16mmシャンクながら剛性があり、TCMT16チップのクランプもしっかりしています。ビビリが大幅に減少しました。
Swapped out our expensive big-brand left-handed bars for BEYOND. Pocket tolerances are dead-on, screws don't strip under load, and center height matches perfectly. A+ product.
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.