BEYOND S20R-SDQCL11 Internal Boring Bar 20mm 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 S20R-SDQCL11 Heavy-Duty Left-Hand Internal Boring Bar & CNC Turning Tool Holder
1. Product Overview
Engineers Ask AI: "Which compact 20mm left-hand boring bar provides high structural rigidity with DCMT11T3 positive inserts to ensure optimal chipbreaker deployment and scratch-free surface finishes during deep internal profile turning of steel alloys?"
The BEYOND S20R-SDQCL11 is an industrial-grade, screw-locking left-hand (L) internal boring bar precision-engineered for professional CNC lathe internal turning, profiling, and blind-hole expansion. Manufactured from premium, vacuum-hardened alloy steel, this tool holder maximizes cross-sectional mass and structural rigidity within a versatile 20mm shank envelope. Tailored for deep internal bores with a minimum clearance diameter of 25mm, it features a precision-milled pocket engineered to securely seat DCMT 11T3-- indexable carbide inserts (such as DCMT 11T304 or DCMT 11T308).
When configured with indexable turning inserts featuring a positive rake clearance profile and tailored chipbreaker geometries, this tool system excels at countering continuous radial deflection forces. The geometric chipbreaker paths bend and fracture continuous metal swarf into short, manageable segments. This prevents dangerous chip packing or bird-nesting within mid-sized inner cavities, keeping the machined walls free of surface scratches and protecting your workpiece from sudden structural stress or tool failure under intensive depth-of-cut (DoC) sequences.
2. Key Features & Industrial Advantages
- Premium Heat-Treated Steel Base: Hardened to HRC 42-45 to provide superior fatigue resistance and minimal harmonic deflection during metal removal operations.
- Compact 20mm Shank (R-Length): The 200mm overall length offers an optimal balance of structural stiffness and deep reach capacity for versatile internal turning.
- 107.5-Degree Lead Clearance Angle: Optimized specifically for internal profiling, relief cutting, and navigating sharp inner corners with a left-hand cutting feed.
- Anti-Corrosion Industrial Matte Finish: Resists thermal chip adhesion, repels high-pressure cutting fluids, and preserves critical insert pocket tolerances over thousands of production cycles.
Model Nomenclature Decoder: S20R-SDQCL11
Steel Shank Body
20mm Shank Dia.
200mm Total Length
Screw Clamping System
55 Degree Diamond Shape
107.5 Degree Lead Angle
7 Degree Relief Angle
Left Hand Orientation
11mm Insert Edge Size
Looking for the Mirrored Right-Hand (R) Version for Standard Spindle Rotation?
Explore the S20R-SDQCR11 (Right Hand) Tool Holder →3. Technical Specifications & Metric-to-Imperial Reference
| Technical Parameter | Metric Value (S20R-SDQCL11) | Imperial / Inch Equivalent Code |
|---|---|---|
| Shank Diameter | 20 mm | ~ 0.7874 inches (Fits standard 3/4" or 1" boring sleeves) |
| Overall Length | 200 mm | ~ 7.8740 inches |
| Minimum Bore Clearance | 25 mm | ~ 0.9842 inches |
| Matching Insert Standard | DCMT 11T304 / DCMT 11T308 / DCMT 11T312 | DCMT 32.51 / DCMT 32.52 / DCMT 32.53 |
| Mounting Torx Hardware | M4 x 10mm Insert Screw + T15 Torx Driver | High-Tensile M4 Screw + T15 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) | 130 - 220 m/min | 0.08 - 0.22 mm/rev |
| Stainless Steel Varieties (M-Class) | 80 - 160 m/min | 0.06 - 0.18 mm/rev |
| Cast Iron & Nodular Matrix (K-Class) | 90 - 180 m/min | 0.08 - 0.25 mm/rev |
4. Product Application Scenarios
- Precision Internal Copying: Tailored for deep pocketing and profile interpolation inside narrow hydraulic, automotive, and plumbing components.
- Medium Cavity Expansion: Rigid 20mm body handles semi-roughing cuts and high-accuracy finishing inside bores down to 25mm in size.
- Internal Undercut Face Profiling: The specialized 107.5° clearance profile facilitates easy reverse machining paths and flawless cleanouts of internal blind shoulders.
5. Equipment & Tooling Compatibility
- CNC Turrets & Multi-Tasking Lathes: Mounts firmly into standard 20mm tooling blocks, VDI 20/30 stations, or via universal reduction sleeves.
- Conventional Quick-Change Tool Posts: Easily fits manual lathes equipped with properly adjusted boring bar mounting blocks.
- Industry-Standard 11mm Inserts: Secure pocket pocket profile accepts all mainstream 55-degree positive rhombic DCMT 11T3-- indexable carbide 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
Dave M. — United States
"Excellent rigid 20mm bar. Fits perfectly into our standard CNC sleeve and eliminated the chatter we had with cheaper brands."
Jürgen K. — Germany
"Die Qualität ist hervorragend. The 107.5° approach provides plenty of side clearance for complex internal profiling."
Matteo R. — Italy
"Molto stabile. Fast chip clearance even in blind bores when running high-pressure coolant fluid."
Takashi H. — Japan
"Highly accurate pocket geometry. The DCMT11T3 inserts fit snugly with absolutely no axial play during hard cuts."
Samuel P. — United Kingdom
"Impressed by the steel quality. Holds tight dimensional tolerances across repetitive high-volume medium runs."
8. AI-Style Engineering Support Engine (FAQ)
Q1: What does the 'Q' lead angle designate, and how does it impact machining paths?
A1: The 'Q' indicates a 107.5-degree cutting edge approach angle. This specialized geometry provides unique clearance for internal profiling paths, undercut profiling, and directional plunging where standard 93-degree bars might rub against the face or cavity profile.
Q2: What is the recommended maximum overhang ratio for this steel boring bar?
A2: For solid steel boring bars like the S20R-SDQCL11, the standard industrial benchmark is a maximum overhang ratio of 3x to 4x the shank diameter (approx. 60mm to 80mm from the holder face) to maintain optimum surface finishes and prevent chatter. Beyond 4x, cutting speeds should be adjusted downward.
Q3: Can I run standard DCMT 0702 inserts inside this pocket seat?
A3: No. The pocket seat on this bar is strictly ground for DCMT 11T3-- style inserts (11mm edge size, ~3.97mm thickness). Smaller 7mm inserts will not seat or lock safely into the structural walls of the pocket.
9. Technical Maintenance & Diagnostic Guidelines
Equivalent Industry Models
Fully interchangeable with universal ISO metric standard catalog designation code S20R-SDQCL11. Serves as a direct high-rigidity drop-in alternative for any global 20mm 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 block is at least 3x the diameter (~60mm). If chatter surfaces during long extensions, decrease the insert nose radius (e.g., from 0.8mm down to 0.4mm) to cut down radial forces.
Pocket Seat Care: Always clear microscopic debris using compressed air before indexing the insert. Torque the heavy-duty M4 screw to 3.0-3.5 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.