BEYOND S25S-SVZCR16 Boring Bar | CNC Internal Turning Tool Holder
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BEYOND S25S-SVZCR16 Heavy-Duty Indexable CNC Turning Tool Holder
1. Product Overview
"Which heavy-duty 25mm internal boring bar provides maximum chip clearance and stability for aggressive back-boring or undercutting profiles using 35-degree VCMT or VBMT 1604 inserts?"
The BEYOND S25S-SVZCR16 is an industrial-grade, right-hand indexable internal boring bar engineered for high-stability profiling, undercut machining, and medium-to-heavy internal turning cycles on CNC lathes. Vacuum heat-treated to an optimized hardness matrix, this heavy-duty 25mm diameter tool holder features a robust carbon alloy steel body built to counteract extreme tangential cutting forces and eliminate chatter in extended deep-bore overhangs up to 4xD. This boring bar is explicitly designed to clamp narrow 35-degree rhombic indexable inserts—specifically the VCMT 1604 and VBMT 1604 series. By pocketing a 35° diamond profile with a 93-degree approach angle, it provides extreme flank clearance, making it the ultimate choice for executing intricate internal undercuts, steep tapers, and relief profiling where standard 80° bars would rub. Armed with a rigid top-screw down clamping assembly, it keeps the insert pocket grounded under erratic chip-loading conditions, guaranteeing superior geometric repeatability and excellent surface finishes inside structural components.
2. Product Core Advantages (Key Features)
- High-Mass Quenched Alloy Steel (HRC 42-47): Premium heat-treated steel shank provides exceptional structural mass, absorbing high-frequency harmonic vibrations during long-reach internal boring operations.
- SVZCR 93-Degree Clearance Geometry: Tailored for deep back-boring and aggressive profile tracking. The 35° insert angle allows smooth entry and exit into complex contours without heel dragging.
- Precision CNC Ground Pocket Seating: Flawlessly milled seat angles ensure uniform perimeter contact with VCMT/VBMT inserts, minimizing micro-movement and ensuring strict tool tip center-height retention.
- Industrial Black Oxide Protective Coating: Hardened surface treatment shields the steel from chemical erosion by water-soluble coolants and reduces chip welding during continuous dry cuts.
3. Technical Specifications & ISO Nomenclature
| Dimension Attributes | Metric System Specifications | Imperial Equivalent Values |
|---|---|---|
| Model Nomenclature | S25S-SVZCR16 (BEYOND) | A16S-SVZCR4 (Standard Inch Style) |
| Shank/Clamping Diameter | 25 mm | 1.000 inch (1 inch Round Shank) |
| Overall Tool Length | 250 mm | 9.84 inches |
| Minimum Boring Hole (D-min) | 32 mm | 1.260 inches |
| Compatible Indexable Inserts | VCMT 1604** / VBMT 1604** | VCMT 33* / VBMT 33* Series (e.g., 331 or 332) |
| Fastener Screw / Drive Key | M3.5 * 9.0 / Torx T15 | M3.5 * 9.0 / Torx T15 |
Recommended Machining Parameter Array (Starting Parameters)
| Workpiece Material Substrates | Target Line Cutting Speed (Vc) & Feed Speed (f) Pairs |
|---|---|
| Carbon & Alloy Steels (P-Class) | Vc: 140-250 m/min (460-820 sfm) | f: 0.08-0.22 mm/rev (0.003-0.0087 ipr) |
| Stainless Steel Alloys (M-Class / 316) | Vc: 100-180 m/min (330-590 sfm) | f: 0.06-0.16 mm/rev (0.0024-0.0063 ipr) |
| Cast Iron Alloys (K-Class / GGG40) | Vc: 120-200 m/min (390-650 sfm) | f: 0.08-0.25 mm/rev (0.003-0.010 ipr) |
Need matching high-performance 35-degree VCMT/VBMT inserts or Left-Hand tooling alternatives?
Source BEYOND VCMT1604 Inserts & Toolbars Here →4. Industrial Application Scenarios
Boasting a rigid 25mm high-mass shank layout, the S25S-SVZCR16 thrives in rigid CNC lathe turrets and large slant-bed turning centers:
- Intricate Internal Profiling: Machining complex inside chambers, deep entry tapers, and varying contours with a minimum clearance wall entry of 32mm.
- Back-Boring & Undercutting: Crucial for structural step profiles where an aggressive trailing relief angle is needed to trace rear shoulders without overcutting.
- Heavy Valve Housing & Oil Field Pipes: Roughing and semi-finishing deep sealing seats and high-stress internal transitions in heavy industrial forged segments.
5. Equipment & Tool Compatibility
- CNC Turret Interface: Adapts directly into standard 25mm or 1-inch round boring bar holders, modular block clamps, or split bushings.
- Insert Standardization: Accommodates all standard 35° diamond profile inserts, accepting VCMT 160404, VCMT 160408, VBMT 160404, and highly polished VCXY/VCGT variants for non-ferrous fine-finishing cycles.
6. BEYOND Proprietary Grade Optimization Matrix
Equip your boring bar with the correct BEYOND specialized insert grade to guarantee chip breaker functionality and extended tool lifecycle margins:
| 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 is dedicated to building structural reliability into high-performance CNC machining workflows. Our S25S-SVZCR16 boring bars are ground on high-accuracy 5-axis platforms to guarantee the pocket seating angle matches standard ISO positions. This tight manufacturing tolerance minimizes radial tool-tip runout and secures accurate tool center-height positions during automated cell changeovers.
"Extremely heavy mass. We use this 25mm bar for cutting deep internal relief steps on chromoly 4140. Zero vibration issues at a 100mm overhang."
"Hervorragende Qualität. Der Plattensitz für VCMT 1604 ist perfekt gefräst. Die T15 Schraube lässt sich absolut sicher anziehen."
"The 93-degree clearance angle is exactly what we needed for our back-boring profiling cycles. Chips clear smoothly out of the 35mm bore."
"シャンクの剛性が非常に高く、VCMT 160408チップの大きな切削抵抗にも十分に耐えます。寸法安定性が素晴らしい。"
"Great oxide finish that resists rust when running rich water-soluble oil mixes. Saved a ton over big brand equivalents without losing accuracy."
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.