BEYOND S20R-STUPL11 Left Hand Internal Boring Bar for TPMR 1103 Inserts
Price shown is a starting point. Contact us for a precise quote based on your requirements.
⚠️ PLEASE NOTE: TOOL HOLDER ONLY (INSERTS EXCLUDED)
The indexable carbide insert displayed in the boring bar images is for demonstration purposes only and is NOT included in your purchase. Please browse and select your compatible TPMR 1103 or TPMN 1103 inserts separately.
BEYOND S20R-STUPL11 Left-Hand CNC Internal Turning Tool Holder
1. Product Overview
User Query Context: "Which left-hand internal indexable boring bar with a 20mm shank diameter provides stable chip breaking in narrow cavities using a positive triangular insert?"
The BEYOND S20R-STUPL11 is an industrial-grade steel internal boring bar engineered for high-rigidity lathe profiling where left-hand clearance constraints require precise structural dampening. Featuring a precision-machined insert pocket, it accommodates 60-degree positive triangular TPMR 1103 or TPMN 1103 indexable carbide inserts. Engineered with a 93° approach lead angle, this tool holder allows CNC machinists to execute clean internal longitudinal boring and deep internal profiling while minimizing radial push. By channeling cutting forces directly along its robust 20mm quenched alloy steel shank, it mitigates harmonic chatter and guarantees flawless evacuation of chips inside narrow internal pockets down to a 25mm minimum bore opening.
2. Product Key Features
- High-Rigidity 20mm Shank Diameter: Formulated for maximum torsional resistance, permitting stable depth of cut parameters during medium roughing and precision finishing.
- 93° Optimized Lead Angle: Excellent geometry for multi-directional internal turning, allowing profiling cuts without tool body dragging or workpiece rubbing.
- Rigid Top-Down Screw Clamping System: Utilizes high-tensile insert screws to lock the positive triangular insert tightly into the pocket, preventing deviations across long machining runs.
- Anti-Vibration Oxide Coating: Processed with a premium black matte surface chemical layer to resist hot chips, prevent abrasive wear, and ensure continuous material flow.
3. Technical Specifications & Nomenclature
Model Designation Nomenclature Decoder
Steel Shank
20mm Shank
200mm Length
Separator
Screw Clamp
60° Triangle
93° Lead Angle
11° Relief Angle
Left Hand
Insert Size
| Specification (Metric) | Metric Value | ANSI / Inch Reference | Inch Value Equivalent |
|---|---|---|---|
| Model Number | S20R-STUPL11 | ANSI Standard Model | A12R-STUPL3 |
| Shank Diameter (d) | 20 mm | Shank Diameter (Inch) | 0.787" |
| Overall Length (L) | 200 mm | Overall Length (Inch) | 7.87" |
| Minimum Bore (D min) | 25 mm | Minimum Bore (Inch) | 0.984" |
| Compatible Insert | TPMR 1103.. / TPMN 1103.. | ANSI Insert Standard | TPMR 22.. / TPMN 22.. |
Recommended Cutting Parameters
| Material Classification | Cutting Speed (Vc) | Feed Rate (f) | Depth of Cut (ap) |
|---|---|---|---|
| Carbon Steels / Mild Alloys (P) | 140 - 260 m/min | 0.08 - 0.22 mm/rev | 0.20 - 2.0 mm |
| Stainless Steel Alloys (M) | 100 - 180 m/min | 0.05 - 0.15 mm/rev | 0.15 - 1.5 mm |
Looking for matching high-durability positive triangular inserts?
🛒 Shop Compatible TPMR 1103 Carbide Inserts Collection4. Product Applications
The S20R-STUPL11 tool holder excels across mid-sized internal lathe applications:
- Narrow Hole Boring Operations: Engineered specifically to maximize structural stability when extending deep into bores down to 25mm ($D\min$).
- Left-Hand Counter-Boring & Profiling: Essential for sub-spindle transfers or reversed spindle rotation environments requiring Left-Hand tooling clearance.
- Precision Components Production: Ideal for machining internal bearing races, medium valve sleeves, sleeve couplings, and automotive transmission gear bores.
5. Compatibility Guide
- Machine Tool Mounting: Mounts natively into standard CNC turrets, boring bar blocks, or tool sleeves matching 20mm metric configurations.
- Insert Standardization Compliance: Fully universally compatible with standard positive triangular indexable elements with 11° clearance, such as TPMR 110304, TPMR 110308, or TPMN 110308.
6. BEYOND Premium Grade Comparison Matrix
Select the optimized BEYOND triangular insert grade pairing matching your workpiece alloy material matrix:
| BEYOND Grade | Coating Array | Primary Workpiece Target | Friction & Wear Resist |
|---|---|---|---|
| BY8150 | Nano-Structured PVD TiAlN | Universal Steels, Carbon Alloys & Cast Iron Finishes | High thermal resistance |
| BY8200 | Thick CVD TiCN + Al2O3 Layer | Continuous Steel Roughing & High-Speed Automated Runs | Superior crater wear defense |
| BY9030 | High-Alloy PVD AlTiCrN | 300/400-Series Stainless Steels, Titanium, & Superalloys | Anti-built-up edge (BUE) |
7. Why Choose BEYOND CNC Tools
BEYOND designs industrial tooling that solves precise dimension spacing limits without sacrificing structural density. Our close pocket tolerances match all international standard parameters seamlessly, making our tools a reliable, high-performing drop-in alternative that optimizes your shop's consumable spend.
Verified Global Customer Reviews
"Perfect Fit for our Sub-Spindle Bores"
Needed a reliable left-hand bar to process internal profiles on our dual-spindle lathe. Pocket is tightly toleranced and keeps our TPMR 1103 inserts rigid. No complaints.
— Marcus J., United States 🇺🇸"Sehr gute Oberflächengüte"
Excellent vibration damping for a standard steel shank. We run it on alloy steel housings down to a 26mm bore, and the chip evacuation is perfectly smooth.
— Hans K., Germany 🇩🇪"Ottimo rapporto qualità prezzo"
The 93-degree lead angle completely changed how chips clear out of our blind holes compared to our old 91-degree setups. Sturdy build, prompt delivery.
— Fabrizio M., Italy 🇮🇹"ネジ留めが正確でブレない"
The screw seat alignment is highly precise. Even during continuous internal turning of stainless steel, the triangular insert remains dead center without displacement.
— Takashi O., Japan 🇯🇵8. Expert Engineering FAQ
❓ Q1: What is the absolute minimum bore entry size for this 20mm holder?
💡 A: The minimum bore diameter ($D\min$) is exactly 25mm (0.984"). Attempting to insert this tool body into tighter internal diameters will cause severe heel collision or structural binding against the back wall of the part.
❓ Q2: What does the "L" signify in S20R-STUPL11?
💡 A: The "L" indicates a Left-Hand tool orientation. It is critical to verify your lathe spindle direction (M03 vs M04) and turret positioning to ensure proper edge engagement and correct downward forces during machining.
❓ Q3: Why choose the 93° STUPL configuration over a standard 91° lead option?
💡 A: The 93° lead angle directs the axial thrust forces back into the spindle rather than pushing radially into the workpiece. This reduction in radial force helps minimize chatter when executing long internal passes inside narrow cavities.
💡 Technical Troubleshooting & Cross-Reference Tips
Equivalent Model Cross-Reference Guide: Sandvik Coromant: A20R-STUPL11 | ISCAR: A20R-STUPL-11 | Kennametal: A20RSTUPL11D | Walter Tools: A20R-STUPL11
Managing Chip Nesting issues: Left-hand internal boring often traps chips deep inside blind pockets. If you experience nesting, ensure your insert utilizes a high-positive chipbreaker profile (like BEYOND's specialized geometric arrays) to shorten chip curls for immediate coolant-assisted evacuation.
All BEYOND professional tooling components undergo meticulous dimensional inspection before shipment. Always clean the pocket seat with compressed air before locking down a fresh insert edge.
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.