{"product_id":"beyond-s12m-stupl11-boring-bar-12mm-cnc-internal-turning","title":"BEYOND S12M-STUPL11 Left Hand Internal Turning Tool Holder | 12mm CNC Boring Bar","description":"\u003cstyle\u003e\n  .beyond-container {\n    font-family: -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, Helvetica, Arial, sans-serif;\n    color: #333333;\n    line-height: 1.6;\n    max-width: 1200px;\n    margin: 0 auto;\n    padding: 15px;\n    box-sizing: border-box;\n  }\n  .beyond-h1-holder {\n    background-color: #47479F;\n    color: #ffffff;\n    padding: 20px;\n    border-radius: 6px;\n    margin-bottom: 25px;\n  }\n  .beyond-h1-holder h1 {\n    margin: 0;\n    font-size: 24px;\n    font-weight: 700;\n    text-transform: uppercase;\n    letter-spacing: 0.5px;\n    color: #ffffff;\n  }\n  .beyond-section {\n    margin-bottom: 35px;\n  }\n  .beyond-section h2 {\n    color: #47479F;\n    border-left: 5px solid #47479F;\n    padding-left: 12px;\n    font-size: 20px;\n    margin-bottom: 15px;\n    font-weight: 600;\n  }\n  .beyond-section h3 {\n    color: #333333;\n    font-size: 16px;\n    margin-top: 20px;\n    margin-bottom: 10px;\n    font-weight: 600;\n  }\n  .beyond-alert-box {\n    background-color: #fff3cd;\n    border: 1px solid #ffeeba;\n    color: #856404;\n    padding: 15px;\n    border-radius: 6px;\n    margin-bottom: 25px;\n    font-weight: bold;\n  }\n  .beyond-grid-box {\n    border: 2px solid #47479F;\n    border-radius: 6px;\n    padding: 20px;\n    margin-bottom: 25px;\n    background-color: #fcfcfd;\n  }\n  .beyond-code-breakdown {\n    display: flex;\n    flex-wrap: wrap;\n    gap: 10px;\n    margin-top: 15px;\n  }\n  .beyond-code-letter {\n    border: 1px solid #47479F;\n    border-radius: 4px;\n    padding: 10px;\n    flex: 1 1 140px;\n    background-color: #ffffff;\n    text-align: center;\n    box-sizing: border-box;\n  }\n  .beyond-code-letter strong {\n    color: #47479F;\n    font-size: 18px;\n    display: block;\n    border-bottom: 1px solid #e0e0e0;\n    padding-bottom: 5px;\n    margin-bottom: 5px;\n  }\n  .beyond-table-wrapper {\n    width: 100%;\n    overflow-x: auto;\n    margin: 15px 0;\n  }\n  .beyond-table {\n    width: 100%;\n    border-collapse: collapse;\n    min-width: 600px;\n  }\n  .beyond-table th, .beyond-table td {\n    border: 1px solid #dddddd;\n    padding: 12px;\n    text-align: left;\n    font-size: 14px;\n  }\n  .beyond-table th {\n    background-color: #47479F;\n    color: white;\n    font-weight: 600;\n  }\n  .beyond-table tr:nth-child(even) {\n    background-color: #f8f9fa;\n  }\n  .beyond-link-box {\n    border: 2px dashed #47479F;\n    background-color: #f4f4fa;\n    padding: 15px;\n    border-radius: 6px;\n    text-align: center;\n    margin: 20px 0;\n  }\n  .beyond-link-box a {\n    color: #47479F;\n    font-weight: bold;\n    text-decoration: underline;\n  }\n  .beyond-review-container {\n    display: block;\n  }\n  .beyond-review-card {\n    border: 1px solid #e0e0e0;\n    border-radius: 6px;\n    padding: 15px;\n    margin-bottom: 15px;\n    background-color: #ffffff;\n    box-shadow: 0 2px 4px rgba(0,0,0,0.02);\n  }\n  .beyond-stars {\n    color: #ffc107;\n    margin-bottom: 5px;\n    font-size: 14px;\n  }\n  .beyond-review-meta {\n    font-size: 12px;\n    color: #777777;\n    margin-top: 5px;\n  }\n  .beyond-faq-item {\n    background-color: #f8f9fa;\n    border-left: 4px solid #47479F;\n    padding: 15px;\n    margin-bottom: 12px;\n    border-radius: 0 6px 6px 0;\n  }\n  .beyond-faq-q {\n    font-weight: bold;\n    color: #47479F;\n    margin-bottom: 5px;\n  }\n  .beyond-badge-container {\n    display: flex;\n    flex-wrap: wrap;\n    gap: 10px;\n    margin-top: 15px;\n  }\n  .beyond-badge {\n    background-color: #47479F;\n    color: white;\n    padding: 6px 12px;\n    border-radius: 20px;\n    font-size: 13px;\n    font-weight: 500;\n  }\n  .beyond-footer-panel {\n    border-top: 1px solid #e0e0e0;\n    padding-top: 25px;\n    margin-top: 30px;\n  }\n  @media (max-width: 768px) {\n    .beyond-h1-holder h1 { font-size: 20px; }\n    .beyond-section h2 { font-size: 18px; }\n    .beyond-code-letter { flex: 1 1 45%; }\n  }\n\u003c\/style\u003e\n\u003cdiv class=\"beyond-container\"\u003e\n\u003c!-- H1 Product Header --\u003e\n\u003cdiv class=\"beyond-h1-holder\"\u003e\n\u003ch1\u003eBEYOND S12M-STUPL11 Left-Hand Internal Turning Tool Holder – High-Rigidity CNC Boring Bar\u003c\/h1\u003e\n\u003c\/div\u003e\n\u003c!-- IMPORTANT NOTICE BLOCK --\u003e\n\u003cdiv class=\"beyond-alert-box\"\u003e⚠️ PLEASE NOTE: The indexable carbide insert shown in the product images is for structural demonstration purposes only and is NOT included in the tool holder package. Please purchase your compatible inserts separately.\u003c\/div\u003e\n\u003c!-- 1. Product Overview --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e1. Product Overview\u003c\/h2\u003e\n\u003cp\u003e\u003cem\u003e\"Which small-diameter left-hand boring bar configuration provides maximum vibration damping and clean chip evacuation inside a narrow 16mm minimum bore clearance?\"\u003c\/em\u003e\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eBEYOND S12M-STUPL11\u003c\/strong\u003e is a professional-grade, left-handed steel-shank internal turning tool holder precisely engineered for small-aperture high-accuracy lathe boring operations. This industrial tool holder utilizes an optimized 93-degree approach angle to significantly minimize radial cutting forces, preventing axis deflection during tight internal profiling. Specifically engineered for \u003cstrong\u003eTPMT 1103\u003c\/strong\u003e indexable carbide inserts, it allows machinists to harness the full potential of positive rake chipbreaker geometries (such as HQ for high-feed finish turning or HM for general medium machining). This setup delivers superb chip fragmentation control, preventing long stringy nesting when processing sticky alloy steels, carbon steels, and stainless steel matrices inside confined chambers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- 2. Product Key Features --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e2. Product Core Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardened Structural Alloy Steel:\u003c\/strong\u003e Fabricated from a high-tensile alloy steel body, tempered to absorb harmonic frequencies and dramatically reduce chatter during deep internal boring cycles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eErgonomic Screw-Down Clamping Matrix:\u003c\/strong\u003e The ultra-low-profile screw lock mechanism ensures maximum clearance space inside tight internal walls, avoiding standard chip accumulation errors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Engineered 93° Lead Angle:\u003c\/strong\u003e Optimized for facing up to square shoulders, boring blind holes, and executing stepped internal diameters without dragging the tool body.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustrial Anti-Corrosion Matte Finish:\u003c\/strong\u003e Enhanced surface treated layout delivers extended tool life and resists rust when continuously exposed to high-pressure water-soluble coolants.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c!-- 3. Technical Specifications --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e3. Technical Specifications \u0026amp; Metric\/Imperial Reference\u003c\/h2\u003e\n\u003cp\u003eEnsuring clear parameter conversion is vital for CNC programming optimization. Below is the precise structural parsing of the \u003cstrong\u003eS12M-STUPL11\u003c\/strong\u003e standard international nomenclature rules:\u003c\/p\u003e\n\u003c!-- Model Code Breakdown Box --\u003e\n\u003cdiv class=\"beyond-grid-box\"\u003e\n\u003cdiv style=\"font-weight: bold; color: #47479f; margin-bottom: 10px;\"\u003eISO Nomenclature Verification Structure:\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-breakdown\"\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eS\u003c\/strong\u003eSteel Shank\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003e12\u003c\/strong\u003e12mm Shank Dia.\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eM\u003c\/strong\u003e150mm Length\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eS\u003c\/strong\u003eScrew Lock System\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eT\u003c\/strong\u003eTriangular Insert\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eU\u003c\/strong\u003e93° Approach\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eP\u003c\/strong\u003e11° Clearance\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003eL\u003c\/strong\u003eLeft-Hand Direction\u003c\/div\u003e\n\u003cdiv class=\"beyond-code-letter\"\u003e\n\u003cstrong\u003e11\u003c\/strong\u003e11mm Edge Length\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Metric vs Imperial \u0026 Models Comparison Table --\u003e\n\u003cdiv class=\"beyond-table-wrapper\"\u003e\n\u003ctable class=\"beyond-table\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter Dimension\u003c\/th\u003e\n\u003cth\u003eMetric System Specification\u003c\/th\u003e\n\u003cth\u003eImperial Equivalent Measurement\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eShank Diameter (d)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e12 mm\u003c\/td\u003e\n\u003ctd\u003e0.4724 inches (Approx. 15\/32\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTotal Tool Length (L)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e150 mm\u003c\/td\u003e\n\u003ctd\u003e5.9055 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMinimum Bore Diameter (D-min)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e16 mm\u003c\/td\u003e\n\u003ctd\u003e0.6299 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCompatible Carbide Insert Layout\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eTPMT 1103 \/ TPMH 1103\u003c\/td\u003e\n\u003ctd\u003eTPMT 2.21 \/ TPMT 2.22\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eClamping Screw Model Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eM2.5 x 6.5\u003c\/td\u003e\n\u003ctd\u003eM2.5 x 0.25 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTorx Key Driver Wrench Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eT8\u003c\/td\u003e\n\u003ctd\u003eT8 Torx Wrench\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c!-- Recommended Cutting Parameters Table --\u003e\n\u003ch3\u003eRecommended Technical Machining Parameters (Speed \u0026amp; Feed Guide)\u003c\/h3\u003e\n\u003cdiv class=\"beyond-table-wrapper\"\u003e\n\u003ctable class=\"beyond-table\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eWorkpiece Material Classification\u003c\/th\u003e\n\u003cth\u003eCutting Speed (Vc) Range\u003c\/th\u003e\n\u003cth\u003eFeed Rate (f) Per Revolution\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCarbon Steel \/ Alloy Steel (HB180-280)\u003c\/td\u003e\n\u003ctd\u003e110 - 200 m\/min (360 - 656 SFM)\u003c\/td\u003e\n\u003ctd\u003e0.05 - 0.15 mm\/rev (0.002 - 0.006 IPR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStainless Steel Matrix (304, 316, 410)\u003c\/td\u003e\n\u003ctd\u003e80 - 140 m\/min (262 - 459 SFM)\u003c\/td\u003e\n\u003ctd\u003e0.04 - 0.10 mm\/rev (0.0015 - 0.004 IPR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCast Iron Grades (GG20, GG25, GGG40)\u003c\/td\u003e\n\u003ctd\u003e90 - 160 m\/min (295 - 525 SFM)\u003c\/td\u003e\n\u003ctd\u003e0.05 - 0.18 mm\/rev (0.002 - 0.007 IPR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c!-- Insert Purchase Internal Link Box --\u003e\n\u003cdiv style=\"border-style: dashed; background-color: #f4f4fa; text-align: center; padding: 15px;\" class=\"beyond-grid-box\"\u003e🔗 Need matching high-performance turning inserts? \u003ca href=\"https:\/\/cnchome-beyond.com\/search?q=TPMT1103\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan style=\"color: #47479f;\"\u003e\u003cspan style=\"text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;\"\u003e\u003cb\u003e\u003cu\u003eClick here to shop BEYOND Original TPMT 110304 \/ TPMT 110308 Carbide Inserts\u003c\/u\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e \u003c\/a\u003ewith premium chipbreaker matrices.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- 4. Product Applications --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e4. Product Application Scenarios\u003c\/h2\u003e\n\u003cp\u003eThe compact left-handed geometry of the S12M-STUPL11 tool holder makes it highly versatile for automated production runs and precision micro-machining workflows:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSmall-Bore Left-Hand Profiling:\u003c\/strong\u003e Essential for sub-spindle configurations or reverse spindle rotation toolpaths where clearance constraints prevent standard tool configurations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Internal Step Boring:\u003c\/strong\u003e The 93-degree lead angle cuts square internal counterbores without scoring or dragging on finished inside walls.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal Chamfering \u0026amp; Valve Profiling:\u003c\/strong\u003e Optimizes complex contoured geometric cuts inside compact valve housings, small hydraulic connectors, and aerospace bushings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c!-- 5. Compatibility --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e5. Compatibility \u0026amp; Equipment Interface\u003c\/h2\u003e\n\u003cp\u003eThis 12mm round-shank boring bar fits seamlessly into standard CNC lathe turret blocks, Swiss-type gang tool posts, boring bar sleeves, or specialized reduction sleeves. It is fully compatible with precision small-lathe and automated machine setups from major global brands (including Haas, Mazak, Doosan, Citizen, Tsugami, and Fanuc systems). Engineered for left-handed tool orientations running front or rear internal turning cycles.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- 6. Material\/Grade Comparison (BEYOND Brand Internal) --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e6. BEYOND Premium Substrate \u0026amp; Grade Selection Matrix\u003c\/h2\u003e\n\u003cp\u003eTo maximize chip control and wear life, pair your S12M-STUPL11 boring bar with the corresponding BEYOND proprietary insert grade tailored to your target material:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBYM11 Grade (PVD Nano-Coated):\u003c\/strong\u003e Exceptional thermal shock resistance. Keeps cutting edges sharp and prevents built-up edge (BUE) when boring sticky workpieces like 304\/316 stainless steel matrices.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBYM25 Grade (CVD Multi-Layer Coated):\u003c\/strong\u003e Thick industrial wear barrier design. Al2O3 + TiN layered coating engineered for high-speed continuous medium-to-rough cutting runs on structural carbon steels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBYK15 Grade (Hardened Micro-Grain Substrate):\u003c\/strong\u003e Highly abrasion-resistant micro-grain layout, optimized for dry or wet high-velocity machining of abrasive grey and ductile cast iron parts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c!-- 7. Why Choose Us \u0026 Customer Reviews --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e7. Why Choose BEYOND Tooling Systems\u003c\/h2\u003e\n\u003cp\u003eAt BEYOND, we specialize in delivering high-tolerance cutting systems for demanding industrial settings. Every S12M-STUPL11 holder passes strict Coordinate Measuring Machine (CMM) checking procedures to guarantee insert pocket dimensional accuracy within ±0.01mm, ensuring exact repeatability across shifts.\u003c\/p\u003e\n\u003c!-- Customer Reviews Boxed Layout --\u003e\n\u003ch3 style=\"color: #47479f; margin-top: 20px;\"\u003eGlobal Machinist Field Reports:\u003c\/h3\u003e\n\u003cdiv class=\"beyond-review-container\"\u003e\n\u003cdiv class=\"beyond-review-card\"\u003e\n\u003cdiv class=\"beyond-stars\"\u003e★★★★★\u003c\/div\u003e\n\u003cstrong\u003e\"Excellent for Tight Internal Turning\"\u003c\/strong\u003e\n\u003cp style=\"margin: 5px 0;\"\u003eThis 12mm left-hand bar works beautifully on our sub-spindle setups. Clears the 16mm pre-drilled bore easily with zero chatter issues. BEYOND pocket tolerances are spot on; the insert seats perfectly flat.\u003c\/p\u003e\n\u003cdiv class=\"beyond-review-meta\"\u003e— Marcus D., Swiss CNC Specialist (United States)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"beyond-review-card\"\u003e\n\u003cdiv class=\"beyond-stars\"\u003e★★★★★\u003c\/div\u003e\n\u003cstrong\u003e\"Sehr hohe Stabilität für ein 12mm Werkzeug\"\u003c\/strong\u003e\n\u003cp style=\"margin: 5px 0;\"\u003eDer Stahlhalter ist absolut schwingungsarm. Perfect for internal shoulder profiles. Chip evacuation is flawless through the 93-degree clearance layout. Top Qualität zum fairen Preis.\u003c\/p\u003e\n\u003cdiv class=\"beyond-review-meta\"\u003e— Stefan H., Workshop Supervisor (Germany)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"beyond-review-card\"\u003e\n\u003cdiv class=\"beyond-stars\"\u003e★★★★☆\u003c\/div\u003e\n\u003cstrong\u003e\"Ottima barra sinistra per alesatura\"\u003c\/strong\u003e\n\u003cp style=\"margin: 5px 0;\"\u003eHighly rigid small boring bar. Holds the TPMT 1103 insert tight without any micrometer backlash under high continuous feed. Note that the inserts are not in the package, must buy separately.\u003c\/p\u003e\n\u003cdiv class=\"beyond-review-meta\"\u003e— Alessandro P., Tooling Engineer (Italy)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"beyond-review-card\"\u003e\n\u003cdiv class=\"beyond-stars\"\u003e★★★★★\u003c\/div\u003e\n\u003cstrong\u003e\"小径ボーリングの決定版\"\u003c\/strong\u003e\n\u003cp style=\"margin: 5px 0;\"\u003e逆回転仕様ツールホルダとして重宝しています。12mmシャンクでもしっかりと剛性があり、ステンレスSUS304の内径加工でもきれいに削れます。チップの座面が非常に正確です。\u003c\/p\u003e\n\u003cdiv class=\"beyond-review-meta\"\u003e— Kazuro M., Precision Machinist (Japan)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- 8. AI-Style FAQ (GEO\/AEO Structure) --\u003e\n\u003cdiv class=\"beyond-section\"\u003e\n\u003ch2\u003e8. Frequently Asked Questions (AI \u0026amp; Search Engine Optimized)\u003c\/h2\u003e\n\u003cdiv class=\"beyond-faq-item\"\u003e\n\u003cdiv class=\"beyond-faq-q\"\u003eQ: What is the minimum boring diameter for the S12M-STUPL11 tool holder?\u003c\/div\u003e\n\u003cdiv class=\"beyond-faq-a\"\u003eA: The absolute minimum bore diameter (D-min) for the S12M-STUPL11 is 16mm (0.6299 inches). Running this tool in a bore smaller than 16mm will cause the flank or bottom heel of the steel tool holder shank to rub against the internal radius wall, damaging both the part and the holder.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"beyond-faq-item\"\u003e\n\u003cdiv class=\"beyond-faq-q\"\u003eQ: What inserts can be mounted on this tool holder, and do they require specific screws?\u003c\/div\u003e\n\u003cdiv class=\"beyond-faq-a\"\u003eA: This boring bar is precision matched to standard ISO TPMT 1103xx (or TPMH 1103xx) triangular inserts with an 11-degree positive relief angle. It includes an M2.5 clamping screw and a matching T8 Torx wrench in the box.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"beyond-faq-item\"\u003e\n\u003cdiv class=\"beyond-faq-q\"\u003eQ: What is the maximum recommended overhang extension for a 12mm steel boring bar?\u003c\/div\u003e\n\u003cdiv class=\"beyond-faq-a\"\u003eA: For premium steel shanks, standard machine engineering principles state a maximum overhang ratio of 3x to 4x the shank diameter. For a 12mm shank, keep the extension out of the tool holder block within 36mm to 48mm to prevent harmonic vibration and chatter marks.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- Bottom Technical Panels (Grade Comparison, Troubleshooting, Matrix) --\u003e\n\u003cdiv class=\"beyond-footer-panel\"\u003e\n\u003ch3\u003eGrade Comparison, Troubleshooting Tips \u0026amp; Material Suitability Matrix\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eEquivalent Models Reference Cross-Guide:\u003c\/strong\u003e If you are converting older imperial workshop tooling layouts to metric industrial standards, this model effectively replaces American Standard designators like \u003cstrong\u003eS08K-STUPL3\u003c\/strong\u003e or custom 1\/2-inch short-shank compact boring configurations.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTroubleshooting Internal Turning Errors:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cem\u003eProblem - Chip Bird-Nesting Inside Confined Bore:\u003c\/em\u003e Slightly increase your feed rate (f) to force proper chip deformation against the insert chipbreaker pocket, or choose a tighter radius configuration (like 0.4mm nose radius).\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eProblem - Rapid Nose Radius Chipping:\u003c\/em\u003e Lower your circumferential surface speed (Vc) index or switch to an advanced multi-layered CVD coated variant (such as the BEYOND BYM25 grade matrix).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eWorkpiece Material Suitability Matrix:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"beyond-badge-container\"\u003e\n\u003cdiv class=\"beyond-badge\"\u003eP - Steel Alloys (Fully Optimized)\u003c\/div\u003e\n\u003cdiv class=\"beyond-badge\"\u003eM - Stainless Steel Matrices (Highly Suitable)\u003c\/div\u003e\n\u003cdiv class=\"beyond-badge\"\u003eK - Cast Iron Variants (Compatible Setup)\u003c\/div\u003e\n\u003cdiv class=\"beyond-badge\"\u003eN - Non-Ferrous Alloys (Excellent with Polished Inserts)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"BEYOND","offers":[{"title":"Default Title","offer_id":43621535645868,"sku":"S12M-STUPL11","price":16.14,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0592\/7328\/1708\/files\/BEYOND_S12M-STUPL11_left_hand_internal_turning_tool_holder_12mm_steel_boring_bar_for_TPMT1103_carbide_inserts_CNC_lathe_internal_profiling.jpg?v=1780551645","url":"https:\/\/cnchome-beyond.com\/products\/beyond-s12m-stupl11-boring-bar-12mm-cnc-internal-turning","provider":"CNCHome-Beyond","version":"1.0","type":"link"}