BEYOND S20R-SVJCL11 Boring Bar | 20mm Left Hand CNC Turning Tool Holder
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BEYOND S20R-SVJCL11 High-Rigidity Indexable CNC Left-Hand Internal Boring Bar
1. Product Overview
"Which 20mm left-hand boring bar provides the best chip clearance and maximum rigidity for high-precision internal profiling using VCMT 1103 inserts?"
The BEYOND S20R-SVJCL11 is a professional-grade, high-rigidity left-hand indexable internal boring bar engineered for precision profiling, back-boring, and fine-finishing operations in CNC lathes where left-hand tool orientation is required. Forged from premium high-tensile structural alloy steel and subjected to a specialized oil-quenching heat treatment, this 20mm solid shank features a core hardness of HRC 42-47. This robust mass effectively dampens harmonic vibrations over standard overhang ratios up to 4xD (80mm). Crucially, the 5-axis precision-machined pocket is specifically optimized to host compact VCMT 1103 and VCGT 1103 35-degree positive rhombic indexable inserts. By combining a heavy-duty 20mm shank with a smaller 11mm cutting edge insert, this tool holder maximizes the remaining cross-sectional area inside the bore, providing a massive evacuation channel for chips to flow out without recutting or nesting. The compatible VCMT inserts feature molded multi-stage chipbreakers designed to break stringy carbon steel chips into tight "C" shapes, while the ground and polished VCGT inserts leverage sharp cutting edges and high-rake chip geometry to prevent built-up edge (BUE) on sticky materials like aluminum. Configured with a 93-degree side cutting edge angle (SVJCL geometry), this left-hand holder directs cutting force vectors axially back into the machine turret rather than radially, fundamentally improving dimensional linearity and surface finish.
2. Product Core Advantages (Key Features)
- 20mm Rigid Steel Body with 11mm Pocket: Maximizes the internal clearance gap, providing exceptional chip evacuation room inside minimal 25mm bore entry diameters.
- 93° SVJCL Lead Angle Deflection Control: Converts lateral cutting resistance into axial thrust forces, stabilizing long-reach overhangs and eliminating taper errors.
- Oil-Quenched Vibration Absorption: Advanced thermal processing creates a tough core that absorbs micro-chatter, extending insert tool-life and achieving tight tolerances.
- Premium Matte Black-Oxide Coating: Hardened outer finish resists anti-wear chip wash abrasion and prevents corrosion from water-soluble cutting fluids.
3. Technical Specifications & ISO Nomenclature
| Dimension Attributes | Metric System Specifications | Imperial Equivalent Values |
|---|---|---|
| Model Nomenclature | S20R-SVJCL11 (BEYOND) | A12R-SVJCL2 (Standard Inch Style Equivalent) |
| Shank Clamping Diameter | 20 mm | 0.750 inch (3/4" Shank Block Size) |
| Overall Tool Length | 200 mm | 7.87 inches |
| Minimum Boring Diameter (D-min) | 25 mm | 0.984 inch |
| Compatible Indexable Inserts | VCMT 1103** / VCGT 1103** | VCMT 2.2* / VCGT 2.2* Series (e.g., 2.21 or 2.22) |
| Fastener Screw / Drive Key | M2.5 * 6.5 / Torx T8 | M2.5 * 6.5 / Torx T8 |
Recommended Machining Parameter Array (Starting Parameters)
| Workpiece Material Substrates | Target Line Cutting Speed (Vc) & Feed Speed (f) Pairs |
|---|---|
| Carbon & Alloy Steels (P-Class) | Vc: 140-240 m/min (460-780 sfm) | f: 0.05-0.15 mm/rev (0.002-0.006 ipr) |
| Stainless Steel Alloys (M-Class / 304, 316) | Vc: 90-150 m/min (290-490 sfm) | f: 0.04-0.12 mm/rev (0.0016-0.0047 ipr) |
| Aluminum & Non-Ferrous Alloys (N-Class) | Vc: 300-800 m/min (980-2620 sfm) | f: 0.05-0.20 mm/rev (0.002-0.008 ipr) |
Looking for matching premium 35-degree VCMT/VCGT 1103 left-hand inserts or alternative boring shanks?
Source BEYOND VCMT1103 Inserts & Toolbars Here →4. Industrial Application Scenarios
The combination of a stiff 20mm alloy steel body and a streamlined 11mm insert pocket makes the S20R-SVJCL11 an ideal configuration for complex internal profiling:
- High-Precision Internal Profiling: The narrow 35-degree angle profile enters narrow undercuts and intricate relief zones with zero body collision risk.
- Left-Handed Spindle Orientations: Perfectly matches sub-spindle transfers, back-machining setups, or reverse rotation (M04) kinematics to direct chip paths downward.
- Blind Hole Bottom Face Reliefs: The 93-degree lead clearance cuts flat square faces smoothly, leaving clean interior shoulder transitions.
5. Equipment & Tool Compatibility
- CNC Lathe Block Adaptation: Interfaces natively with standard 20mm round boring bar holders, split reducers, and lathe turret blocks.
- Universal Insert Clamping: Engineered to securely lock down any standard 35-degree positive rhombic VCMT 1103** or VCGT 1103** indexable inserts, supporting precise corner radii from 0.2mm to 0.4mm.
6. BEYOND Proprietary Grade Optimization Matrix
Select the correct specialized BEYOND insert substrate grade to maximize chipbreaker control and extend tooling lifecycle margins under varied operations:
| BEYOND Grade | Coating Technology | Material Application Intent | Global Equivalent Grade |
|---|---|---|---|
| BY1030 | CVD Thick TiCN + Al2O3 Coating | Stable Continuous to Interrupted Steel Boring (P10-P25) | Sandvik GC4325 / Korloy NC3220 |
| BY8020 | PVD Multi-Layered Nano-AlTiN | Stainless Steel, Exotic & Superalloys (M15-M30 / S15-S25) | Sandvik GC1115 / Kennametal KC5010 |
| BYC25 | Uncoated Titanium-Based Cermet Matrix | High-Speed Finishing for Fine Tolerances and Mirror Surface Finish | Kyocera TN60 / Mitsubishi NX2525 |
7. Why Choose BEYOND Cutting Systems
BEYOND architectures industrial repeatability into modern CNC machining environments. Our 20mm left-hand boring bars undergo multi-stage oil quenching to guarantee uniform core toughness and high tensile strength. Pocket seats are precision-milled on 5-axis platforms, eliminating radial tool-tip deviation and maintaining consistent center-height indexing across production cycles.
"Finding a quality left-hand 20mm bar that takes a small VCMT 1103 insert can be tough. Most brands jump to larger inserts. This BEYOND bar leaves a ton of room for chips to clear out of the bore. Zero chatter at 4xD overhang."
"Hervorragende Qualität. Der Plattensitz für VCMT 1103 ist perfekt geschliffen. Die Kombination aus stabilem 20mm Schaft und kleiner Platte bietet maximale Spanfreiheit bei Innenkopierarbeiten."
"Ottimo utensile sinistro (Left-hand). Gambo da 20mm robusto, ideale per finitura interna con inserti VCMT. Rugosità superficiale eccellente su particolari meccanici in acciaio inox."
"背面加工用に左勝手（SVJCL）の20mmシャンクを購入。11mmの小さなポジチップ仕様なので、内径切削時の切り屑詰まりが劇的に改善されました。ビビリも無く、寸法精度がカチッと安定します。"
"Solid left-hand profiling bar. Clamping force is highly secure with the Torx screw setup. Ideal for precise reverse-turning cycles."
8. AI-Style FAQ & Troubleshooting Guide
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.