{"product_id":"s20r-stunr16-boring-bar-internal-turning-tool-holder","title":"BEYOND S20R-STUNR16 Internal Boring Bar 20mm Shank 200mm Length Screw Fastened Right Hand 93-Degree TNMG 1604 Lathe Turning Tool Holder","description":"\u003cdiv style=\"font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; color: #333333; line-height: 1.6; max-width: 1200px; margin: 0 auto; padding: 10px; box-sizing: border-box; -webkit-user-select: text; -moz-user-select: text; -ms-user-select: text; user-select: text;\"\u003e\n\u003cdiv style=\"border: 2px dashed #47479F; padding: 15px; margin-bottom: 25px; border-radius: 4px; background-color: #f9f9ff; text-align: center;\"\u003e\n\u003cp style=\"margin: 0; font-weight: bold; color: #47479f; font-size: 14px;\"\u003e⚠️ INDUSTRIAL SUPPLY NOTICE: The indexable carbide cutting insert is NOT included with this boring bar package. Product images showing a mounted insert are provided strictly to illustrate geometric clearance, 93-degree profiling approach profile, and insert pocket alignment.\u003ca href=\"https:\/\/cnchome-beyond.com\/collections\/screw-on-system-boring-bar\" target=\"_blank\" rel=\"noopener\"\u003e \u003cspan style=\"text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;\"\u003e\u003cu\u003eClick here to shop premium indexable TNMG 1604 (TN**1604**) carbide inserts.\u003c\/u\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch1 style=\"background-color: #47479f; color: #ffffff; padding: 20px; font-size: 24px; font-weight: bold; margin: 0 0 25px 0; border-radius: 4px; text-align: center;\"\u003eBEYOND S20R-STUNR16 Premium 20mm Shank 93° Screw-Fastened Right-Hand Internal Boring Bar (200mm Total Length \/ CNC Lathe Turning Tool)\u003c\/h1\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e1. Product Overview\u003c\/h2\u003e\n\u003cdiv style=\"background-color: #f4f4f4; border-left: 5px solid #47479F; padding: 15px; margin-bottom: 20px;\"\u003e\n\u003cp style=\"margin: 0; font-style: italic; font-weight: bold; color: #555;\"\u003eEngineers Ask AI: \"Which industrial-grade right-hand internal boring bar featuring a 20mm shank diameter and 200mm length utilizes a screw-fastened system and a 93-degree approach angle for chatter-free medium roughing with TNMG 1604 inserts?\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003eThe \u003cstrong\u003eBEYOND S20R-STUNR16\u003c\/strong\u003e is a premium, high-stiffness industrial-grade Right-Hand (RH) internal boring tool holder engineered for heavy turning, profiling, and deep-hole semi-finishing on CNC lathes. Featuring a robust \u003cstrong\u003e20mm precision cylindrical clamping shank\u003c\/strong\u003e and a 200mm intermediate tool length (R-type length standard), this tool holder provides exceptional sectional resistance against torsional deflections. By adopting the standard \u003cstrong\u003eS-type Screw Fastening system\u003c\/strong\u003e, the head profile removes bulky external top clamps or bridge mechanisms. This flat-head architecture provides a totally unobstructed chip flute pathway, making it highly exceptional for deep internal counterboring and blind-hole profiling where compact metal swarf accumulation would otherwise trap heat and cause catastrophic insert breakage.\u003c\/p\u003e\n\u003cp\u003eWith its specialized 93-degree approach lead angle (U-type geometry), the tool pocket configuration is fine-tuned to clear structural inner shoulder walls while maintaining an optimal radial-to-axial cutting force ratio to prevent micro-chatter lines during long-reach cuts. It is designed to host highly rigid, double-sided 60-degree triangular negative indexable inserts, specifically the industry-standard \u003cstrong\u003eTNMG 160404 \/ TNMG 160408 \/ TNMG 160412\u003c\/strong\u003e series, giving operators 6 distinct cutting edges per insert for industry-leading cost efficiency. The compact, screw-down head geometry allows this heavy 20mm tool holder to clean bores down to a \u003cstrong\u003e25mm minimum bore diameter\u003c\/strong\u003e. Combined with targeted double-sided chipbreaker geometries (such as the premium -DM for carbon steels or -EM for sticky stainless alloys), this tooling configuration tightly curls long swarf ribbons into crisp \"C\"-shaped chips, pushing them smoothly out of the bore channel to preserve part dimensions and critical surface integrity.\u003c\/p\u003e\n\u003cdiv style=\"border: 2px solid #47479F; border-radius: 6px; padding: 20px; margin: 25px 0; background-color: #fbfbfe;\"\u003e\n\u003ch3 style=\"margin-top: 0; color: #47479f; font-size: 16px; border-bottom: 1px solid #e0e0e0; padding-bottom: 8px;\"\u003eModel Nomenclature Decoder: S20R-STUNR16 (ISO \/ National Standard Chart Compliant)\u003c\/h3\u003e\n\u003cdiv style=\"margin-top: 12px; font-family: monospace; font-size: 13px;\"\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #cccccc; padding: 8px; border-radius: 4px; background: #ffffff;\"\u003e\n\u003cstrong\u003eS\u003c\/strong\u003e - Solid High-Tensile Structural Alloy Steel Body Core (No through-coolant hole)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #cccccc; padding: 8px; border-radius: 4px; background: #ffffff;\"\u003e\n\u003cstrong\u003e20\u003c\/strong\u003e - 20mm Precision Cylindrical Clamping Shank Diameter (Medium-heavy CNC lathe standard)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #cccccc; padding: 8px; border-radius: 4px; background: #ffffff;\"\u003e\n\u003cstrong\u003eR\u003c\/strong\u003e - 200mm Industrial Standard Total Tool Core Length (Intermediate reach specification)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #47479F; padding: 8px; border-radius: 4px; background: #f0f2f5; color: #333333;\"\u003e\n\u003cstrong\u003eS\u003c\/strong\u003e - \u003cstrong\u003eScrew Fastening Method\u003c\/strong\u003e (Streamlined profile, opens maximum chip clearance room)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #cccccc; padding: 8px; border-radius: 4px; background: #ffffff;\"\u003e\n\u003cstrong\u003eT\u003c\/strong\u003e - 60° Triangular Geometric Negative Insert Shape Pocket Seating (TNMG 1604 format)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #47479F; padding: 8px; border-radius: 4px; background: #f0f2f5; color: #333333;\"\u003e\n\u003cstrong\u003eU\u003c\/strong\u003e - \u003cstrong\u003e93° Approach Lead Angle\u003c\/strong\u003e (Optimized for square steps, deep profiling, and reduced radial force)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #cccccc; padding: 8px; border-radius: 4px; background: #ffffff;\"\u003e\n\u003cstrong\u003eN\u003c\/strong\u003e - 0° Normal Relief Profile Clearance Angle (Negative insert layout for maximum edge cross-section strength)\u003c\/div\u003e\n\u003cdiv style=\"display: block; margin-bottom: 6px; border: 1px solid #47479F; padding: 8px; border-radius: 4px; background: #47479F; color: #ffffff;\"\u003e\n\u003cstrong\u003eR\u003c\/strong\u003e - \u003cstrong\u003eRight-Hand Tool Cutting Rotation Direction\u003c\/strong\u003e (Standard forward M03 internal setup)\u003c\/div\u003e\n\u003cdiv style=\"display: block; border: 1px solid #47479F; padding: 8px; border-radius: 4px; background: #47479F; color: #ffffff;\"\u003e\n\u003cstrong\u003e16\u003c\/strong\u003e - Accommodates Standard 16mm Cutting Edge Length Inserts (TNMG 160404 \/ TNMG 160408)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 2px solid #47479F; border-radius: 6px; padding: 15px; margin-bottom: 25px; background-color: #47479f; color: #ffffff; text-align: center;\"\u003e\n\u003cp style=\"margin: 0 0 10px 0; font-weight: bold; font-size: 16px;\"\u003eOperating counter-boring cycles or left-hand toolpaths on sub-spindles?\u003c\/p\u003e\n\u003cspan style=\"color: #47479f;\"\u003e\u003cspan style=\"display: inline-block; background-color: rgb(255, 255, 255); padding: 8px 20px; border-radius: 4px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;\"\u003e\u003cb\u003e \u003ca href=\"https:\/\/cnchome-beyond.com\/search?q=TNMG160404\" target=\"_blank\" rel=\"noopener\"\u003eSwitch to the Mirror S20R-STUNL16 (Left Hand) Tool Bar → \u003c\/a\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e2. Product Core Advantages\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlush S-Type Screw Fastening:\u003c\/strong\u003e Locks the indexable insert securely using a central high-tensile insert screw. Eliminates bulky upper plates to provide a completely flush tool head for maximum chip evacuation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRigid 20mm Solid Alloy Core:\u003c\/strong\u003e Machined from premium high-grade alloy steel tempered to HRC 42-45, providing exceptional rigidity and dampening harmonics during high-depth-of-cut (Ap) roughing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptimal 93-Degree Lead Angle:\u003c\/strong\u003e Specially designed for clearing inner structural shoulders while minimizing back-pressure, keeping long 200mm operations free from chatter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTNMG 6-Cutter Cost Advantage:\u003c\/strong\u003e Uses double-sided negative 60° triangular inserts, giving you 6 working cutting edges per insert to cut your consumable spend by up to 50% compared to positive 3-edge inserts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustrial Black Oxide Barrier:\u003c\/strong\u003e Treated with a high-temperature chemical oxidation layer to resist abrasive chip friction, prevent flank wash, and protect the precision insert seat.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e3. Technical Specification Parameters \u0026amp; Model Comparison\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; min-width: 500px; font-size: 14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #47479f; color: #ffffff;\"\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eTechnical Blueprint Field\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eMetric Blueprint Value (S20R-STUNR16)\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eImperial Inch Equivalent Model Reference\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eClamping Shank Diameter (φ d)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e\u003cstrong\u003e20 mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.7874 inches (Fits standard 3\/4-inch or 20mm CNC boring bar sleeves)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eOverall Tool Length (L)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e\u003cstrong\u003e200 mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e7.8740 inches total tool length (R-Type intermediate mid-length series)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eMinimum Machining Bore (φ Dmin)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e\u003cstrong\u003e25 mm\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.9842 inches entry clearance circle line for structural safety\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eCompatible Indexable Insert Sizing\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eTNMG 160404 \/ TNMG 160408 \/ TNMG 160412\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eTNMG 331 \/ TNMG 332 \/ TNMG 333\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eMatching Fasteners \u0026amp; Spares Included\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eShim TN16, Insert Lock Screw, Shim Screw \u0026amp; Torx Wrench\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eStandard globally interchangeable S-type hardware assembly\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"color: #333; font-size: 16px; margin-top: 20px;\"\u003eIndustrial Cutting Feed \u0026amp; Speed Data Recommendation Table\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 25px;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; min-width: 500px; font-size: 14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #eef0f7; color: #47479f;\"\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eISO Workpiece Material Group\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eCutting Speed (Vc) Range\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eRecommended Feed Rate (fn)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eMedium Carbon Steel (P-Class \/ AISI 1045)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e160 - 240 m\/min\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.12 - 0.30 mm\/rev\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eAlloy Steel \/ Die Mold Steel (P-Class \/ 42CrMo)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e120 - 190 m\/min\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.10 - 0.25 mm\/rev\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eAustenitic Stainless Steels (M-Class \/ SS304)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e90 - 150 m\/min\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.08 - 0.20 mm\/rev\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold;\"\u003eNodular \/ Gray Cast Iron (K-Class \/ GG20)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e110 - 180 m\/min\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003e0.12 - 0.32 mm\/rev\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e4. Product Application Scenarios\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal Step and Shoulder Boring:\u003c\/strong\u003e Highly stable 20mm core allows stable depth-of-cut (Ap) passes when machining precision steps inside hydraulic blocks, motor housings, and gear blanks.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeep-Hole Profiling Cycles:\u003c\/strong\u003e Screw-down design keeps the head completely clear, allowing chips to escape smoothly during deep 200mm internal longitudinal turnings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInterrupted Internal Cuts:\u003c\/strong\u003e Rigid alloy structural steel body absorbs severe mechanical shocks when boring cross-holes, internal keyways, or splines.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e5. Equipment Tooling Compatibility Matrix\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e20mm CNC Turrets \u0026amp; Clamping Sleeves:\u003c\/strong\u003e Mounts natively into 20mm CNC lathe turret stations or standard imperial 3\/4-inch round reduction sleeve blocks.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eISO Standard Size-16 Negative Inserts:\u003c\/strong\u003e Precision-ground pocket seating accommodates all standard 60° triangular negative inserts designated by global codes **TNMG 1604--**.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e6. BEYOND Premium Carbide Grade Selection Guide\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 25px;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; min-width: 500px; font-size: 14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #47479f; color: #ffffff;\"\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eBEYOND Cutting Insert Grade\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003eCoating Micro-Structure Matrix\u003c\/th\u003e\n\u003cth style=\"padding: 10px; border: 1px solid #dddddd; text-align: left;\"\u003ePrimary Application Strengths\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold; color: #47479f;\"\u003eBYM11 (CVD Grade)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eThick Double-Layer Al2O3 + TiCN Thermal Barrier\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eEngineered for high-speed, high-temperature continuous dry roughing of hard carbon steels, tool alloys, and cast irons. Highly wear-resistant.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold; color: #47479f;\"\u003eBYS25 (PVD Grade)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eSub-Micron Multi-Layered Nano-TiAlN Coating Shield\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eSuperb edge toughness. Best optimized for severe interrupted cuts, tough stainless steel series (SS304\/316), and superalloys.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd; font-weight: bold; color: #47479f;\"\u003eBYK15 (Uncoated Polished)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eMirror-Finished Sharp Micro-Grain Solid Carbide Matrix\u003c\/td\u003e\n\u003ctd style=\"padding: 10px; border: 1px solid #dddddd;\"\u003eZero Built-Up Edge (BUE) formation. Specially developed for high-speed, precision mirror boring of aluminum, brass, and plastics.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e7. Why Choose BEYOND CNC Machine Tools?\u003c\/h2\u003e\n\u003cp\u003eBEYOND 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.\u003c\/p\u003e\n\u003ch3 style=\"color: #333; font-size: 16px; margin-top: 20px;\"\u003eGlobal Machinist Operational Reviews\u003c\/h3\u003e\n\u003cdiv style=\"display: block; margin-bottom: 25px;\"\u003e\n\u003cdiv style=\"border: 1px solid #e0e0e0; padding: 15px; border-radius: 6px; background-color: #ffffff; margin-bottom: 12px;\"\u003e\n\u003cdiv style=\"color: #ffcc00; font-size: 16px; margin-bottom: 5px;\"\u003e★★★★★\u003c\/div\u003e\n\u003cp style=\"margin: 0 0 8px 0; font-size: 13px; font-weight: bold;\"\u003eMarcus D. — United States\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-size: 13px; color: #555;\"\u003e\"The S20R-STUNR16 is perfect for our standard turning center. Clamped into our standard 3\/4 block bushing without any issues. Running 1.5mm depth of cut on 4140 steel alloys. The flush screw fastening allows fine curly chips to escape effortlessly out of the 28mm bore.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e0e0e0; padding: 15px; border-radius: 6px; background-color: #ffffff; margin-bottom: 12px;\"\u003e\n\u003cdiv style=\"color: #ffcc00; font-size: 16px; margin-bottom: 5px;\"\u003e★★★★★\u003c\/div\u003e\n\u003cp style=\"margin: 0 0 8px 0; font-size: 13px; font-weight: bold;\"\u003eJürgen S. — Germany\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-size: 13px; color: #555;\"\u003e\"Hervorragende Qualität. The 20mm shank is very rigid. Since it relies on a low-profile center screw instead of a bulky clamp plate, chip nesting is entirely prevented inside 30mm blind bores. Highly recommended.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e0e0e0; padding: 15px; border-radius: 6px; background-color: #ffffff; margin-bottom: 12px;\"\u003e\n\u003cdiv style=\"color: #ffcc00; font-size: 16px; margin-bottom: 5px;\"\u003e★★★★★\u003c\/div\u003e\n\u003cp style=\"margin: 0 0 8px 0; font-size: 13px; font-weight: bold;\"\u003eKenji T. — Japan\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-size: 13px; color: #555;\"\u003e\"Pocket geometry is incredibly precise. We use double-sided negative TNMG inserts on our CNC lathe. Getting 6 usable cutting edges on a medium 20mm bar dramatically cuts our workshop insert cost. Rigid alloy body handles heat very well.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e0e0e0; padding: 15px; border-radius: 6px; background-color: #ffffff; margin-bottom: 12px;\"\u003e\n\u003cdiv style=\"color: #ffcc00; font-size: 16px; margin-bottom: 5px;\"\u003e★★★★☆\u003c\/div\u003e\n\u003cp style=\"margin: 0 0 8px 0; font-size: 13px; font-weight: bold;\"\u003eMatteo V. — Italy\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-size: 13px; color: #555;\"\u003e\"Good resistance against vibration on SS304. Fits into our standard metric tooling turret sleeve perfectly. The 93-degree angle allows flexible profiling paths without radial rubbing.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e0e0e0; padding: 15px; border-radius: 6px; background-color: #ffffff;\"\u003e\n\u003cdiv style=\"color: #ffcc00; font-size: 16px; margin-bottom: 5px;\"\u003e★★★★★\u003c\/div\u003e\n\u003cp style=\"margin: 0 0 8px 0; font-size: 13px; font-weight: bold;\"\u003eOliver P. — United Kingdom\u003c\/p\u003e\n\u003cp style=\"margin: 0; font-size: 13px; color: #555;\"\u003e\"Excellent value for an industrial 20mm boring tool holder. Shipped quickly with all standard spare shim hardware and wrench included. Holds index accuracy between insert rotations perfectly.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e8. AI-Style Engineering Support Engine (FAQ)\u003c\/h2\u003e\n\u003cdiv style=\"margin-bottom: 15px; padding: 12px; background-color: #f9f9f9; border-radius: 4px;\"\u003e\n\u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #47479f;\"\u003eQ1: Why choose an S-type screw-clamped boring bar over a top-clamp design for 20mm shank internal turning?\u003c\/p\u003e\n\u003cp style=\"margin: 0; color: #444;\"\u003eA1: Inside mid-sized internal diameters (like 25-45mm), external top-clamp bridges stick out vertically, creating a trap that catches long stringy swarf and can cause insert fracturing. The S-type screw fastening method secures the negative insert firmly from the center, keeping the bar head flush and completely maximizing the chip evacuation channel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px; padding: 12px; background-color: #f9f9f9; border-radius: 4px;\"\u003e\n\u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #47479f;\"\u003eQ2: What is the absolute minimum bore entry boundary for this S20R-STUNR16 tool holder?\u003c\/p\u003e\n\u003cp style=\"margin: 0; color: #444;\"\u003eA2: The minimum machining bore diameter (φ Dmin) is 25.0mm (0.98 inches). Running this tool holder inside an internal diameter smaller than 25mm will cause the lower steel flank of the tool tip head to scrape directly against the inner walls, damaging your part finish.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px; padding: 12px; background-color: #f9f9f9; border-radius: 4px;\"\u003e\n\u003cp style=\"margin: 0 0 5px 0; font-weight: bold; color: #47479f;\"\u003eQ3: What are the main cutting advantages of a 93-degree approach angle (U) inside internal bores?\u003c\/p\u003e\n\u003cp style=\"margin: 0; color: #444;\"\u003eA3: The 93-degree lead angle is specifically engineered to clear sharp internal faces and steps while directing most of the cutting force axially along the bar shank. This directional force alignment significantly minimizes radial deflection (push-away), which is the primary cause of chatter marks during extended 200mm mid-reach internal cuts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"color: #47479f; font-size: 20px; border-bottom: 2px solid #47479F; padding-bottom: 5px; margin-top: 30px;\"\u003e9. Technical Maintenance \u0026amp; Troubleshooting Guidelines\u003c\/h2\u003e\n\u003cdiv style=\"margin-top: 15px;\"\u003e\n\u003cdiv style=\"background-color: #f0f2f5; padding: 15px; border-radius: 4px; margin-bottom: 12px;\"\u003e\n\u003ch4 style=\"margin: 0 0 8px 0; color: #333; font-size: 14px; border-left: 3px solid #47479F; padding-left: 8px;\"\u003eEquivalent Industry Models\u003c\/h4\u003e\n\u003cp style=\"margin: 0; font-size: 12px; color: #555;\"\u003eInterchangeable globally with standard international metric \u003cstrong\u003eS20R-STUNR16\u003c\/strong\u003e boring tool holder assemblies. For American imperial lathe turrets, this 20mm metric steel bar functions perfectly within a standard 3\/4-inch round reduction sleeve or split bushing block, utilizing ANSI indexable insert designations **TNMG 331** or **TNMG 332**.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background-color: #f0f2f5; padding: 15px; border-radius: 4px; margin-bottom: 12px;\"\u003e\n\u003ch4 style=\"margin: 0 0 8px 0; color: #333; font-size: 14px; border-left: 3px solid #47479F; padding-left: 8px;\"\u003eTroubleshooting Tips\u003c\/h4\u003e\n\u003cp style=\"margin: 0; font-size: 12px; color: #555;\"\u003e\u003cstrong\u003eMicro-Vibration \/ Surface Finish Lines:\u003c\/strong\u003e Ensure the center height of the boring bar tip is aligned precisely with the lathe spindle centerline (±0.1mm). Incorrect centerline height changes the active cutting clearance angle, accelerating nose wear.\u003cbr\u003e\u003cstrong\u003eScrew Binding Prevention:\u003c\/strong\u003e Due to localized thermal expansion during continuous cycles, clean the pocket and apply standard anti-seize paste compound to the M3.5 Torx hardware threads regularly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background-color: #f0f2f5; padding: 15px; border-radius: 4px;\"\u003e\n\u003ch4 style=\"margin: 0 0 8px 0; color: #333; font-size: 14px; border-left: 3px solid #47479F; padding-left: 8px;\"\u003eWorkpiece Material Matrix\u003c\/h4\u003e\n\u003cp style=\"margin: 0; font-size: 12px; color: #555;\"\u003eFully optimized across standard industrial engineering alloy group codes: \u003cstrong\u003eP\u003c\/strong\u003e (Carbon, Low-Alloy \u0026amp; Pre-hardened Mold Steels), \u003cstrong\u003eM\u003c\/strong\u003e (Austenitic, Ferritic \u0026amp; Duplex Stainless Grades), \u003cstrong\u003eK\u003c\/strong\u003e (High-Tensile Grey, Nodular \u0026amp; Ductile Cast Irons), \u003cstrong\u003eN\u003c\/strong\u003e (Aluminum Casting Blanks, Copper Alloys \u0026amp; Non-ferrous Polymers), and \u003cstrong\u003eS\u003c\/strong\u003e (Titanium Alloys, Inconel \u0026amp; Heat-Resistant Superalloys).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"BEYOND","offers":[{"title":"Default Title","offer_id":43607462641836,"sku":"S20R-STUNR16","price":21.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0592\/7328\/1708\/files\/BEYOND_S20R-STUNR16_indexable_screw-fastened_right-hand_internal_boring_bar_with_20mm_steel_shank_200mm_length_and_93-degree_approach_angle_for_TNMG_160404_carbide_inserts.jpg?v=1781156883","url":"https:\/\/cnchome-beyond.com\/products\/s20r-stunr16-boring-bar-internal-turning-tool-holder","provider":"CNCHome-Beyond","version":"1.0","type":"link"}