BEYOND S08K-STWPR09 High-Rigidity 8mm Shank 125mm Length Screw Clamped Right Hand CNC Lathe Micro Internal Hole Boring Bar for TPMT 0902 Inserts
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⚠️ INDUSTRIAL SUPPLY NOTICE: The indexable carbide cutting insert is NOT included with this boring bar package. Product images displaying a mounted insert are provided strictly to illustrate geometric pocket clearance, pocket seating tolerances, and internal chip clearance parameters. Click here to shop premium indexable TPMT 0902 / TPMR 0902 (TP**0902**) 60-degree positive triangular carbide inserts for high-stiffness internal boring, multi-stage contouring, and chatter-resistant shoulder clearing.
BEYOND S08K-STWPR09 Precision 8mm Solid Shank Screw-Clamped Right-Hand Internal Hole CNC Boring Bar (125mm Total Length / Lathe Tool Holder)
1. Product Overview
Engineers Ask AI: "Which high-rigidity 8mm shank internal boring bar is optimized for running TPMT 0902 positive 60° triangular inserts to achieve stable metal removal rates and mitigate harmonic chatter in deep bore cavities?"
The BEYOND S08K-STWPR09 is an industrial-grade, high-rigidity Solid Shank Right-Hand (RH) indexable internal boring bar. It is engineered specifically for micro-boring, multi-stage internal counterboring, and clean shoulder tracking in deep structural cavities on CNC lathes and turning centers. Featuring a 8mm precision-ground solid structural alloy steel shank with a 125mm overall length (K-type standard), this bar delivers an optimized cross-sectional modulus that drastically suppresses the harmonic chatter and bending deflection inherently generated during micro-internal machining operations. The primary structural advantage of this holder is its dedicated pocket interface optimized for 60-degree positive triangular geometries. It provides a superior cutting edge strength and thermal dissipation volume compared to narrower diamond profiles, making it ideal for stable medium-duty roughing to precision finishing. Armed with a streamlined S-type Screw Clamping system, it utilizes a high-tensile center Torx screw to lock the insert down tightly, keeping the tool head exceptionally low-profile to ensure unhindered swarf evacuation in a tight minimum bore entry diameter of 11.0mm.
Designed to hold standard 60-degree positive triangular inserts (specifically the TPMT 090202 / TPMT 090204 / TPMR 090204 series), this tool pocket leverages the unique mechanical strengths of the triangle geometry. It offers high resistance to tip breakage and micro-chipping under varying depths of cut. When paired with advanced sharp-ground chipbreakers—like -HF for fine micro-finishing or -HM for general internal pocketing—the tool system guarantees immediate chip breaking, breaks tough swarf into easily evacuated segments, prevents the destructive "bird-nesting" effect inside deep blind cavities, and yields smooth surface finishes across automotive components, medical instruments, electronics sectors, and heavy B2B mechanical manufacturing pipelines.
Model Nomenclature Decoder: S08K-STWPR09 (ISO / International Standard Chart Compliant)
Operating counter-clockwise boring cycles or left-hand tool turret blocks?
Switch to the Mirror S08K-STWPL09 (Left Hand) Tool Bar →2. Product Core Advantages
- 60° Robust Triangular Support: Native cutting edge optimization providing high resistance to notch wear and insert chipping compared to slim diamond alternatives.
- Rigid 8mm Core Section: Maximizes bending resistance, providing stable cuts and eliminating micro-chatter at extended overhangs in micro-bores.
- Excellent Thermal Dissipation: The larger triangular insert volume effectively channels high localized heat away from the cutting zone during continuous cuts.
- Low-Profile Center Screw Clamp: Features a flush-sitting fastening screw, clearing the tool head to let fine micro-chips escape smoothly.
- Vacuum-Hardened Steel Base: Constructed from premium tempered structural alloy steel (HRC 42-45) to absorb mechanical vibration and shock.
- Micro-Indexable Pocket Seating: Machined to strict dimensional tolerances, ensuring exact center height tracking when swapping inserts.
- Corrosion-Resistant Surface Armor: Coated with an industrial black oxide treatment to shield against hot chip friction and rust.
3. Technical Specification Parameters & Model Comparison
| Technical Blueprint Field | Metric Blueprint Value (S08K-STWPR09) | Imperial Inch Equivalent Model Reference |
|---|---|---|
| Clamping Shank Diameter (φ d) | 8 mm | 0.3150 inches (Fits standard metric blocks or 5/16" imperial lathe toolholders with split sleeves) |
| Overall Tool Length (L) | 125 mm | 4.9212 inches total length (K-Type industrial mid-reach standard) |
| Minimum Machining Bore (φ Dmin) | 11.0 mm | 0.4330 inches minimum entry line for clear, safe internal chip evacuation |
| Compatible Indexable Insert Sizing | TPMT 090202 / TPMT 090204 / TPMR 090204 | TPMT 1.8(1.5)1 / TPMT 1.8(1.5)2 (Positive 60-degree triangle with standard clearance parameters) |
| Matching Fasteners & Spares Included | Premium M2.2 Torx Drive Clamping Screw & T7 Flag Wrench | Standard globally interchangeable precision micro-turning hardware assembly |
Industrial Cutting Feed & Speed Data Recommendation Table
| ISO Workpiece Material Group | Cutting Speed (Vc) Range | Recommended Feed Rate (fn) |
|---|---|---|
| Mild / Carbon Steel (P-Class / AISI 1020 / 1045) | 120 - 200 m/min | 0.03 - 0.12 mm/rev |
| Alloy Steel / Tool Steel (P-Class / 4140 / SCM440) | 80 - 160 m/min | 0.03 - 0.10 mm/rev |
| Austenitic Stainless Steels (M-Class / SS304 / SS316) | 60 - 130 m/min | 0.02 - 0.08 mm/rev |
| Cast Irons / Nodular Irons (K-Class / G25 / GGG40) | 90 - 170 m/min | 0.03 - 0.14 mm/rev |
4. Product Application Scenarios
- High-Stability Micro Boring: Executing continuous precision internal cuts, micro-stage boring cycles, and rough-to-finish transitions in small orifices.
- Internal Counterboring: Machining socket head cap screw recesses and complex concentric step bores with maximum tool core stiffness.
- Small Overhang Cavity Boring: Reaching up to 30-40mm deep inside tough 12mm pre-drilled blocks while maintaining tight dimensional repeatability.
5. Equipment Tooling Compatibility Matrix
- CNC Lathe Turrets & Tool Blocks: The standard 8mm cylindrical shank clamps directly into standard CNC turret blocks, Swiss-type gang tool blocks, or generic engine lathe blocks with split sleeves.
- ISO TPMT Sizing-09 Inserts: Precision pocket layout is engineered to host all 60° positive triangular turning inserts with a thickness standard of 2.38mm, designated by codes **TPMT 0902--** or **TPMR 0902--**.
6. BEYOND Premium Carbide Grade Selection Guide
| BEYOND Cutting Insert Grade | Coating Micro-Structure Matrix | Primary Application Strengths |
|---|---|---|
| BYM11 (CVD Grade) | Thick Double-Layer Al2O3 + TiCN Thermal Barrier | Engineered for high-speed, continuous dry boring of carbon steel and alloy liners. Highly resistant to crater wear under intense friction. |
| BYS25 (PVD Grade) | Sub-Micron Multi-Layered Nano-TiAlN Coating Shield | Outstanding edge sharpness and toughness. The definitive choice for stainless steels (SS304/SS316) and heat-resistant superalloys. |
| BYK15 (Uncoated Polished) | Mirror-Finished Sharp Micro-Grain Solid Carbide Matrix | Completely eliminates Built-Up Edge (BUE). Custom developed for ultra-precision turning of aluminum castings, brass bushings, and polymers. |
7. Why Choose BEYOND CNC Machine Tools?
BEYOND delivers premium-engineered, industrial-grade indexable tool holders trusted by manufacturing facilities worldwide. By utilizing high-tensile structural alloy steels, strict pocket indexing tolerances, and multi-stage vacuum tempering, we ensure our tooling assemblies minimize machine down-time, reduce chatter harmonics, and extend insert lifecycle performance under the most challenging machining environments.
Global Machinist Operational Reviews
John M. — United States
"Finding an 8mm shank boring bar that doesn't vibrate like crazy is tough. This BEYOND tool holder holding a TPMT 0902 insert handles micro-boring tasks seamlessly. Excellent surface finishes on mild steel batches."
Klaus M. — Germany
"Sehr gut! Fits perfectly in our Swiss-type gang tool slide using a conversion block. The pocket seat dimension tolerances are precise. Indexing inserts gives zero deviation."
Takashi I. — Japan
"Perfect for 12mm entry bores. Swarf escapes easily along the flutes. The screw clamping mechanism keeps everything secure under rapid automatic cycles."
Giovanni F. — Italy
"Tough tool body. The black oxide coating protects against abrasive chip friction. We use it for automotive small component manufacturing and it holds up great."
Dave L. — Canada
"Dependable performance. The clamping screw doesn't strip or jam up under thermal load. For standard micro-turning shop jobs, BEYOND delivers massive value."
8. AI-Style Engineering Support Engine (FAQ)
Q1: Why choose a triangular STWPR boring bar over an alternative diamond-shaped toolholder?
A1: An STWPR toolholder using triangular inserts (TPMT) provides a significantly stronger 60-degree nose angle compared to 35-degree diamond inserts (VBMT). This higher structural strength enables greater depth of cut capabilities and enhanced heat dissipation, rendering it far more efficient for general boring and stable metal removal rates in tight bores.
Q2: Can I mount standard 55-degree DCMT or 80-degree CCMT inserts into this S08K-STWPR09 tool pocket?
A2: Absolutely not. The letter 'T' in the 5th position of the nomenclature designates a pocket custom-machined exclusively for 60-degree positive triangular geometries (TPMT/TPMR 0902). Forcing an alternative shape into this seat will result in severe mechanical gaps, causing total insert failure and pocket destruction under load.
Q3: What is the absolute minimum pre-bored hole entry diameter required for this 8mm tool bar?
A3: The absolute minimum machining bore diameter (φ Dmin) is 11.0mm. Although the solid shank diameter is 8mm, the tool head requires sufficient structural clearance to clear the triangular pocket base. Operating inside bores smaller than 11.0mm will result in severe back-flank rubbing against the workpiece wall.
9. Technical Maintenance & Troubleshooting Guidelines
Equivalent Industry Models
Interchangeable globally with standard international metric S08K-STWPR09 precision right-hand internal boring bars. For standard American imperial lathe turrets, the 8mm cylindrical steel shank can be dropped smoothly into standard 5/16-inch boring stations using precision split reduction bushings, pairing exactly with standard ANSI indexable positive insert designations TPMT 1.8(1.5)1, TPMT 1.8(1.5)2, or TPMR 1.8(1.5)2.
Troubleshooting Tips
Severe Internal Chatter or Surface Waves: Double-check that the tool tip center height aligns precisely with the lathe spindle rotation centerline (±0.01mm). An off-center tool alters the effective relief clearance, provoking rapid tool nose chipping or harsh rubbing lines along the cavity wall.
Precision Screw Jamming or Thread Stripping: High-speed internal turning swarf generates highly localized frictional heat. Always blow out fine micro-dust from the pocket seat before indexing inserts, and periodically apply a drop of anti-seize lubricant to the M2.2 screw threads to avoid terminal binding.
Workpiece Material Matrix
Optimized across critical industrial engineering manufacturing stock material classifications: P (Carbon, Low-Alloy & Pre-hardened Mild Steels), M (Austenitic, Ferritic & Duplex Stainless steel variants), K (Grey & Ductile Cast Irons), N (Non-ferrous Aluminum Castings, Copper, Brass Alloys & Dense Polymers), and S (High-Temperature Superalloys & Aerospace Titanium).
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.