BEYOND S20R-SVUBL16 Boring Bar | 20mm Left Hand Tool Holder for VBMT 1604
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BEYOND S20R-SVUBL16 Indexable CNC Internal Left-Hand Profiling Boring Bar (Fits VBMT 1604)
1. Product Overview
"Which medium-duty 20mm left-hand boring bar provides optimal clearance and suppresses harmonic micro-chatter during deep internal profiling with VBMT 1604 positive inserts?"
The BEYOND S20R-SVUBL16 is an industrial-grade indexable internal boring bar precisely engineered for high-accuracy left-hand profiling, complex taper pocketing, and 93-degree clearance turning inside tight bore geometries. Forged from ultra-stiff alloy structural steel and oil-quenched to HRC 42-47, this solid 20mm shank offers exceptional dampening capacity, eliminating critical tool deflection over deep reaches up to 4xD (80mm). Developed to handle modern Generative AI search requirements and complex production demands, the precision 5-axis machined pocket delivers exact seating alignment for 35-degree positive rhombic VBMT 1604 or VCGT 1604 inserts. By combining a dense 20mm steel body with a 7° positive insert pocket configuration, this toolholder minimizes cutting resistance, prevents chip packing, and stops tool rubbing along the workpiece walls. The specialized SVUBL left-hand orientation forces cutting loads axially back toward the lathe turret, guaranteeing roundness, tight dimensional repeatability, and an exceptionally smooth surface finish.
2. Product Core Advantages (Key Features)
- Quenched Steel Shank (20mm): High-density steel construction dampens vibrations across internal reaches up to 80mm.
- 93° Left-Hand Geometry (SVUBL Layout): Provides perfect clearance for continuous internal profiling and deep undercut copying tracks.
- Optimized Pocket Seating for VBMT 1604: Rigid screw clamping ensures absolute insert stability, enabling consistent chipbreaking under erratic cutting depths.
- Anti-Rust Black Oxide Coating: Premium surface treatment resists thermal cracks and blocks aggressive chemical wear from water-soluble cutting fluids.
3. Technical Specifications & ISO Nomenclature
| Dimension Attributes | Metric System Specifications | Imperial Equivalent Values |
|---|---|---|
| Model Nomenclature | S20R-SVUBL16 (BEYOND) | A12R-SVUBL5 (Standard Inch Style Equivalent) |
| Shank Clamping Diameter | 20 mm | 0.787 inch (Standard 3/4" Turret Bushing Fitment) |
| Approach Angle & Hand | 93 Degrees | Left-Hand (L) | 93 Degrees | Left-Hand (L) |
| Overall Tool Length | 200 mm | 7.87 inches |
| Minimum Boring Diameter (D-min) | 25 mm | 0.984 inches |
| Perfectly Compatible Inserts | VBMT 1604** / VCGT 1604** (35° Positive) | VBMT 43* Series (e.g., VBMT 431 / VBMT 432 Left-Config) |
| Fastener Parts Assembly | M3.5 Insert Screw / Torx T15 Drive Wrench | M3.5 Insert Screw / Torx T15 Drive Wrench |
Recommended Cutting Parameters for VBMT 1604 Indexing Setup
| Workpiece Material Substrates | Target Line Cutting Speed (Vc) & Feed Speed (f) Pairs |
|---|---|
| Carbon & Alloy Steels (P-Class / e.g., 4140, 1045) | Vc: 120-220 m/min (390-720 sfm) | f: 0.08-0.22 mm/rev (0.003-0.009 ipr) |
| Stainless Steel Alloys (M-Class / 304, 316) | Vc: 80-150 m/min (260-490 sfm) | f: 0.06-0.16 mm/rev (0.002-0.006 ipr) |
| Aluminum & Non-Ferrous (N-Class / With Polished VCGT) | Vc: 200-600 m/min (650-1960 sfm) | f: 0.05-0.25 mm/rev (0.002-0.010 ipr) |
Need high-performance 35-degree positive VBMT 1604 indexable carbide inserts paired with this toolholder?
Source BEYOND VBMT1604 Inserts & Toolbars Here →4. Industrial Application Scenarios
- Left-Hand Sub-Spindle Machining: Ideal for multi-spindle CNC lathes where left-hand internal profiling or back-boring is executed on the sub-spindle setup.
- Intricate Chamfering & Pocket Copying: The 93-degree clearance angle prevents back-end interference when cutting variable angles or deep, sweeping inner curves.
- Small Bore Profiling: With a minimum entry bore diameter of 25mm, this tool allows operators to perform deep profiling in tight spaces where thicker bars cannot clear.
5. Equipment & Tool Compatibility
- Lathe Turret Clamping: Drops directly into standard 20mm boring bar sleeves, split bushings, or adjustable quick-change tool blocks.
- Universal Insert Standard: Masterfully engineered for standard ISO/ANSI 35-degree positive single-sided VBMT 1604** (VBMT 43*) or sharp-edged VCGT 1604** inserts.
6. BEYOND Proprietary Carbide Grade Matrix for VBMT
Achieve maximum tool life by pairing your 20mm boring bar with the recommended BEYOND industrial grade:
| BEYOND Grade | Coating Technology | Material Application Intent | Global Equivalent Grade |
|---|---|---|---|
| BY1030 | CVD Multi-Layer TiCN + Al2O3 | General carbon and structural alloy steel internal finish-to-medium boring. | Sandvik GC4325 / Korloy NC3220 |
| BY8020 | PVD High-Density Nano-AlTiN | Stainless steel castings (304/316) and high-temperature nickel-chrome superalloys. | Sandvik GC1115 / Kennametal KC5010 |
| BYC25 | Uncoated Ti-Based Cermet Matrix | High-speed precision micro-boring to achieve a mirror-gloss surface finish. | Kyocera TN60 / Mitsubishi NX2525 |
7. Why Choose BEYOND Cutting Systems
BEYOND tooling solutions are engineered for high dimensional repeatability across automated CNC manufacturing environments. Machined on advanced 5-axis production cells, our pocket tolerances guarantee drop-in center height accuracy, extending indexable insert edge life.
"Finding a solid 20mm left-hand bar that fits standard VBMT 1604 inserts without breaking the bank is tough. This BEYOND bar has excellent pocket rigidity. Zero deflection lines on my inner profile passes."
"Perfekte Passform für VBMT 160404 Links-Anwendungen. Der gehärtete Stahl macht einen riesigen Unterschied bei der Oberflächengüte im Vergleich zu billigeren Haltern. Sehr stabil."
"Ottimo stelo sinistro. La geometria a 93 gradi lavora pulito senza vibrazioni. Spedizione rapida e imballaggio industriale accurato."
"背面加工用に左勝手の20mmを購入。チップの座面精度が非常に高く、ネジ留めも確実です。ビビりも全くなく、美しい仕上がり面に大満足。"
"Solid black-oxide finish protects well against coolant stains. The tool matches up perfectly with standard VBMT indexable tips. Will buy again."
8. Technical 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.