BEYOND S20R-STWPR11 Internal Turning Tool Holder for TPMR 1103 Inserts
Free shipping on all orders.
Check compatibility: Confirm the model and dimensions before ordering.
Need help choosing? Contact us before ordering.
💰 Bulk savings 2-9 pcs · 6% OFF | 10+ pcs · 12% OFF
⚠️ PLEASE NOTE: CARBIDE INSERTS NOT INCLUDED
The indexable carbide insert shown within the boring bar pocket is for visual demonstration purposes only. It is NOT included in the purchase of the tool holder. Please purchase your compatible TPMR 1103 or TPMN 1103 inserts separately.
BEYOND S20R-STWPR11 Internal Turning Tool Holder
1. Product Overview
User Query Context: "Which internal boring bar with a 20mm shank is best for high-feed chip breaking in deep carbon steel bores using a triangular TPMR insert?"
The BEYOND S20R-STWPR11 is an industrial-grade, heavy-duty steel internal boring bar designed for precision cutting inside standard cylindrical bores. Engineered with a stable 60-degree triangular insert pocket profile, it utilizes TPMR 1103 or TPMN 1103 indexable carbide inserts. With a 91° approach angle, this tool holder excels at clean internal longitudinal turning and squaring inner shoulders. It channels high-feed cutting forces directly into the robust 20mm alloy steel shank, mitigating radial deflection and eliminating chip packing or chip nesting loops inside deep metal pockets.
2. Product Key Features
- High-Tensile Quenched Steel Shank: Crafted from structural alloy steel treated to HRC 42-45, ensuring excellent rigidity and resistance to bending under high mechanical loads.
- 91° Execution Lead Angle: Specially engineered for straight internal through-boring and profiling routines, providing perfect side clearance that avoids tool rubbing.
- Top-Down Screw Clamping System: Utilizes a specialized precision Torx screw setup to clamp the triangular insert down firmly, ensuring minimal vibration even during interrupted cuts.
- Corrosion-Resistant Black Oxide Treatment: The burnished surface finish repels sticky metal chips, scales off coolant corrosion, and improves long-term service life.
3. Technical Specifications & Nomenclature
Model Designation Nomenclature Decoder
Steel Shank
20mm Shank
200mm Length
Separator
Screw Clamp
60° Triangle
91° Lead Angle
11° Clearance
Right Hand
Insert Size
| Specification (Metric) | Metric Value | ANSI / Inch Reference | Inch Value |
|---|---|---|---|
| Model Number | S20R-STWPR11 | ANSI Standard Model | A12R-STWPR3 |
| Shank Diameter (d) | 20 mm | Shank Diameter (Inch) | 0.787" (~3/4 inch) |
| Overall Length (L) | 200 mm | Overall Length (Inch) | 7.87" |
| Minimum Bore (D min) | 25 mm | Minimum Bore (Inch) | 0.984" (~1 inch) |
| 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 / Structural Steel (P) | 120 - 240 m/min | 0.08 - 0.25 mm/rev | 0.2 - 1.5 mm |
| Stainless Steel Alloys (M) | 80 - 160 m/min | 0.06 - 0.18 mm/rev | 0.15 - 1.2 mm |
Need the matching triangular carbide inserts for this boring bar?
🛒 Shop Compatible TPMR 1103 Carbide Inserts Collection4. Product Applications
The S20R-STWPR11 tool holder is optimized for medium-diameter internal lathe operations:
- Internal Longitudinal Boring: Built for widening internal holes down to 25mm ($D\min$) with high operational accuracy.
- Inner Face Shoulder Turning: The 91° profile allows clean back-boring and machining of flat internal steps without creating a taper.
- Heavy-Duty Infrastructure Machining: Widely deployed across heavy industrial applications including automotive transmission gears, hydraulic cylinder tubes, and heavy machinery sleeves.
5. Compatibility Guide
- CNC Equipment Integration: Easily clamps into standard 20mm round boring bar holders, sleeve adaptors, or CNC lathe turret block stations.
- Insert Standardization: Fully compatible with ISO-standard indexable triangular inserts with positive 11° clearance angles, including TPMR 110304, TPMR 110308, or TPMN 110304 profiles.
6. BEYOND Premium Grade Comparison Matrix
Match your S20R-STWPR11 holder with the optimized BEYOND insert carbide grade for your targeted metal group:
| BEYOND Grade | Coating Properties | Target Workpiece Matrix | Cutting Conditions |
|---|---|---|---|
| BY8150 | Advanced PVD TiAlN | General Purpose Steels & Pre-hardened Alloy Die Steel | Stable/Light Interrupted |
| BY8200 | Multi-layer CVD TiCN+Al2O3 | Carbon Steel Roughing & High-Speed Continuous Turning | High-Speed Continuous |
| BY9030 | Heat-Resistant PVD AlTiCrN | Austenitic Stainless Steels, Inconel, & Superalloys | Medium-to-Low Speeds |
7. Why Choose BEYOND CNC Tools
BEYOND delivers high-durability metalworking solutions that combine precision mechanical engineering with cost-effective production scaling. Our tool holders meet full ISO/ANSI cross-compatibility standards, providing a direct substitute for tier-one brands while significantly reducing your factory overhead.
Verified Global Customer Reviews
"Heavy-Duty Rigidity"
This 20mm boring bar handles heavy cut depths inside our 4140 steel sleeves without pushing away or chattering. Very solid product.
— Dave K., United States 🇺🇸"Präzise Plattensitz"
The pocket tolerancing for the TPMR triangular insert is perfectly flat. The insert indexing remains highly accurate between shifts.
— Hans W., Germany 🇩🇪"Ottima rimozione truciolo"
The 91-degree approach clears curly metal chips effortlessly out of deep bores. Torx mounting screw is durable and doesn't strip.
— Matteo B., Italy 🇮🇹"優れたコストパフォーマンス"
The surface coating quality is exceptional. Outlasts our standard tool holders on production lines at a fraction of the cost.
— Takashi O., Japan 🇯🇵8. Expert Engineering FAQ
❓ Q1: Why use a 60-degree triangular TPMR insert instead of a 35-degree diamond variant?
💡 A: Triangular shapes provide a larger 60° internal tip point angle compared to a 35° configuration. This dramatically enhances tool edge strength, allowing for larger depths of cut and roughing passes without premature edge fracturing.
❓ Q2: What is the optimal overhang projection ratio for the S20R steel boring bar?
💡 A: For solid steel internal shanks, the maximum safe working overhang length is 3 times the diameter ($20\text{ mm} \times 3 = 60\text{ mm}$). For depths exceeding $4D$, carbide-shank boring bars should be sourced to prevent mechanical deflection.
💡 A: Yes, the pocket layout supports standard positive triangular insert configurations with an 11-degree relief angle. This means you can drop in standard ISO or ANSI grade inserts effortlessly.
💡 Technical Troubleshooting & Cross-Reference Tips
Equivalent Model Cross-Reference Guide: Sandvik Coromant: A20R-STWPR11 | ISCAR: A20R-STWPR-11 | Kennametal: A20RSTWPR11D | Walter Tools: A20R-STWPR11
Managing Chip Nesting: If you observe metal ribbon packaging around the tool body during deep operations, increase your feed rate ($f$) or select a specialized ground geometric chipbreaker insert. This applies more mechanical pressure against the chip wall to break it cleanly.
All BEYOND production tools undergo strict mechanical inspection cycles. Ensure your lathe turret sleeve is fully wiped of debris before clamping down the tool shank.
Need Help With BEYOND Inserts?
Looking for a BEYOND equivalent, alternative grade, or sample catalog? Our CNC specialists have helped 50+ manufacturers in aerospace, automotive, and medical machining source the right tooling at 30–50% lower cost than OEM prices.
This BEYOND insert is in stock. 24-hour quote response. ISO 9001 certified. Ships from Hangzhou in 3–7 days.
Technical FAQ & Buying Guide
When choosing CNC cutting tools, check the full model code, dimensions, grade and selected variant before ordering. Do not rely on the product image alone.
For carbide inserts, tool holders, drills and end mills, compare the mounting dimensions, connection type and manufacturer's specifications with your holder or machine. If you are unsure, share your existing part number and machining application with us before ordering.
Check the product listing for the selling unit, pack quantity and included components. If it is unclear whether the price is per piece or per pack, or whether a tool body and inserts are sold separately, contact us before purchasing.
Select cutting speed, feed rate and depth of cut using the relevant manufacturer's recommendations for your tool model, workpiece material, machine conditions and coolant method. The same settings are not suitable for every product or application.
Our automatic quantity discount is 6% off for 2–9 items and 12% off for 10 or more items, based on the total product quantity in the cart. Other offers may not combine with this discount; check the applicable offer conditions.
According to our shipping policy, orders are typically processed and shipped within 1–3 business days after confirmation. Delivery generally takes 5–20 business days, depending on your destination and shipping method. Customs clearance or unforeseen delays may affect delivery times. A tracking number is sent by email after shipment.