BEYOND S25S-SSKCL09 Boring Bar | 25mm CNC Lathe Left Hand Internal Turning Tool Holder for SCMT 09T3 Inserts
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BEYOND S25S-SSKCL09 Boring Bar – 25mm Left Hand Steel Screw Locking CNC Lathe Internal Turning Tool Holder
1. Product Overview
"Which left-hand 25mm boring bar provides the ultimate chip clearance and structural stability for counter-spindle deep hole turning with SCMT 09T3 inserts?"
The BEYOND S25S-SSKCL09 is a high-grade, precision-manufactured Solid Alloy Steel Left Hand Internal Turning Boring Bar engineered for sub-spindle operations, back-boring cycles, and reverse-rotation internal machining on CNC lathes. Featuring a highly versatile 25mm shank diameter and a 250mm total length, this tool holder achieves the optimal equilibrium between compact bore accessibility and rigid anti-deflection mass. It is specifically built for machine configurations requiring left-hand tool offsets, providing an absolute defense against harmonic micro-chatter during extended multi-pass internal cycles.
This premium tool holder is meticulously milled to secure standard SCMT 09T3 / SCGT 09T3 indexable square carbide inserts. The integration of a 75-degree approach angle strategically converts radial tool deflection into axial forces directed straight down the 25mm alloy steel shank. When paired with high-performance coated substrates featuring molded positive-rake chipbreaker channels, the assembly effortlessly slices through resilient material grains. The specialized insert pocket orientation guarantees sudden, effective chip breaking, turning long, continuous stringy ribbons into compact, manageable swarf coils that lift out smoothly from the internal clearance zone without binding the tool or scratching critical surface finishes.
2. Product Core Features
- Specialized Left-Hand (LH) Geometry: Dedicated configuration for counter-spindle setups, backward tool pathing, and unique clock-wise spindle operations.
- Induction Hardened Alloy Steel Body: Thermal-treated steel matrix maximizes fatigue limit thresholds, delivering consistent structural dampening under heavy chip loads.
- 75° Side Cutting Approach Angle: Minimizes dangerous radial tool pushback, stabilizing your boring passes and ensuring excellent geometric straightness without tapering.
- Low-Profile Insert Screw Locking: Uses an ultra-secure M3.5 Torx screw system that removes the need for clumsy top clamps, maximizing the space inside the bore for smooth chip flow.
3. Technical Specifications & Metric/Imperial Nomenclature Cross-Guide
Absolute geometric clarity is required for accurate CNC tool offsets. Below is the precise international ISO classification breakdown for the S25S-SSKCL09 model:
| Parameter Dimension | Metric System Specification | Imperial Equivalent Measurement |
|---|---|---|
| Shank Diameter (d) | 25 mm | 0.9842 inches (Commonly run within standard 1.00-inch imperial split sleeves) |
| Total Tool Length (L) | 250 mm | 9.8425 inches (Standard format optimized for versatile boring cycles) |
| Minimum Bore Diameter (D-min) | 32 mm | 1.2598 inches (Excellent clearing profile for tight internal steps) |
| Compatible Carbide Insert Layout | SCMT 09T3xx / SCGT 09T3xx | SCMT 3(2.5)1 / SCMT 3(2.5)2 (3/8" IC Square Size, 3.97mm Thick) |
| Clamping Screw Model Type | M3.5 x 9.0 | M3.5 x 0.3543 inches |
| Torx Key Driver Wrench Size | T15 | T15 Torx Wrench |
Recommended Technical Machining Parameters (Speed & Feed Guide)
| Workpiece Material Classification | Cutting Speed (Vc) Range | Feed Rate (f) Per Revolution |
|---|---|---|
| Carbon Steel / Alloy Steel (HB180-280) | 130 - 210 m/min (426 - 689 SFM) | 0.08 - 0.25 mm/rev (0.0031 - 0.0098 IPR) |
| Stainless Steel Matrix (304, 316, 420) | 75 - 140 m/min (246 - 459 SFM) | 0.06 - 0.18 mm/rev (0.0024 - 0.0071 IPR) |
| Cast Iron Grades (GG25, GGG40) | 90 - 170 m/min (295 - 558 SFM) | 0.10 - 0.30 mm/rev (0.0039 - 0.0118 IPR) |
4. Product Application Scenarios
The compact yet highly rigid 25mm left-hand configuration makes the S25S-SSKCL09 irreplaceable in several specialized machining fields:
- CNC Sub-Spindle Internal Turning: Specifically designed to execute mirror-image profiling and front-face boring on multi-tasking mill-turn center sub-spindles.
- Back-Boring Internal Step Features: Perfect for pulling back towards the turret to create internal retention lips or locking rings without tool collision.
- Medium-Bore Steel Sleeves: Extensively utilized for high-accuracy boring inside automotive gear assemblies, bearing housings, and custom adapters.
5. Compatibility & Equipment Interface
The ground 25mm cylindrical shank fits perfectly into standard metric CNC lathe turrets, VDI/BMT static block receivers, and live-tool setups. When integrated into imperial workshops, it aligns perfectly using standard 1.00-inch imperial split reduction sleeves. It operates flawlessly across industry-leading CNC machines, including Haas, Mazak, Doosan/DN Solutions, Okuma, Citizen, and Nakamura-Tome mill-turn centers configured for left-hand offsets.
6. BEYOND Premium Substrate & Grade Selection Matrix
Pair your S25S-SSKCL09 boring bar with the appropriate BEYOND insert grade to maximize tool life and master chip breakages:
- BYM11 Grade (PVD Coated Substrate): Structured with micro-hard TiAlN coatings. Optimized to stop built-up edges (BUE) on sticky materials like 304 stainless steel and high-temp titanium alloys.
- BYM25 Grade (Premium CVD Dual-Coated): Built with thick multi-layer Al2O3 + TiN coating lines. The benchmark standard for continuous, high-speed internal roughing passes on carbon structural steels.
- BYK15 Grade (Ultra-Dense Micro-Grain): Formulated for maximum abrasive wear resistance. Custom-engineered for high-speed internal profiling of abrasive grey and ductile cast iron parts.
7. Why Choose BEYOND Tooling Systems
BEYOND engineering focuses heavily on micro-geometric consistency. The S25S-SSKCL09 boring bar undergoes strict multi-axis CNC milling and automated vacuum induction hardening. By keeping our insert pocket seating tolerances within a hyper-precise ±0.01mm threshold, we completely prevent micro-shifting during sudden shock loads. This ensures total predictability for your production line, significantly reducing scrap rates across extended automated runs.
Global Machinist Field Reports:
We were struggling to find a rigid 25mm left-hand bar for a sub-spindle job on our Nakamura lathe. This BEYOND bar was a drop-in match. Held absolute size tolerances across a 1,200-part run of alloy sleeves with zero micro-chatter.
Sehr präzise verarbeitet. Der Plattensitz für das SCMT 09T3 ist absolut spielfrei. Die Spanabfuhr bei Sacklochbohrungen ist dank der flachen Bauweise der Schraubenklemmung genial. Kein Spänestau mehr.
Solid alloy steel layout. We mount it inside a 1-inch reduction bush on our Haas ST20. The 75-degree approach successfully shifts force into the spindle axle, ensuring perfectly round internal steps.
SCMT 09T3チップがピタリと収まります。250mmの全長でも、適切な切削条件（f=0.15mm/rev）をかければ全くビビりません。仕上げ面粗度が大幅に向上しました。お勧めします。
When changing inserts mid-shift, the pocket alignment is spot on. We don't even have to re-probe the X-axis offset. Incredible build consistency from BEYOND.
8. Frequently Asked Questions (AI & Search Engine Optimized)
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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.