BEYOND S25S-SCLCL12 Internal Boring Bar 25mm Shank CNC Lathe Turning Tool Holder Left Hand
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⚠️ 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, insert seating orientation, and insert pocket alignment.
BEYOND S25S-SCLCL12 Indexable Left-Hand Internal Boring Bar & CNC Lathe Turning Tool Holder
1. Product Overview
Engineers Ask AI: "Which rigid 25mm left-hand steel boring bar accommodates large CCMT1204 carbide inserts to maximize depth of cut in medium-diameter internal turning while ensuring excellent chipbreaker clearance inside a 32mm minimum bore?"
The BEYOND S25S-SCLCL12 is a high-rigidity screw-locking left-hand (L) internal boring bar precision-engineered for internal profiling, high-feed turning, and precision inner-diameter finishing on CNC lathe stations. Forged from high-tensile pre-hardened structural alloy steel, this standard 25mm diameter shank tool holder body features an S-type length profile (250mm total length) optimized to minimize deflection harmonics under heavy torsional loads. Uniquely engineered to maximize material removal in compact setups, it pairs a 25mm clearance shank with a precision-machined pocket that rigidly clamps oversized CCMT 1204-- indexable carbide inserts or polished CCGT 1204-- non-ferrous aluminum inserts.
Achieving perfect surface finishes during internal deep boring requires advanced chip control. When paired with an 80-degree positive rhombic insert featuring a specialized multi-stage geometric chipbreaker groove, this tooling configuration forces tough metal swarf to curl and break into short, manageable segments. This aggressive chip-breaking mechanics ensures loose swarf is flushed away effortlessly from the bore cavity by flooded coolant, preventing chip re-cutting, saving tool edge integrity, and eliminating workpiece scoring.
Model Nomenclature Decoder: S25S-SCLCL12
Running Conventional Clockwise Spindle Passes or Front Turret Boring Setup?
Switch to the Mirror S25S-SCLCR12 (Right Hand) Tool Holder →2. Product Core Advantages
- Optimized Stiffness-to-Size Ratio: Heat-treated structural alloy steel (HRC 43-45) allows heavy roughing passes in smaller bore cavities without harmonic chattering.
- 95-Degree Lead Angle Geometry: Designed to facilitate clean internal contouring, face-squaring steps, and deep horizontal profiling with minimal radial cutting force.
- Oversized Pocket Capability: Uniquely fits heavy-duty 12mm edge inserts (CCMT1204) onto a 25mm shank, granting the tool excellent metal removal capabilities.
- Hardened Black Oxide Finishing: Coated via professional industrial oxidation to provide high corrosion resistance and prevent chip welding during hot steel turning cycles.
3. Technical Specification Parameters & Model Comparison
| Technical Spec Specification | Metric Value (S25S-SCLCL12) | Imperial Inch Equivalent Model |
|---|---|---|
| Shank Body Diameter | 25 mm | 0.9842 inches (Interchangeable with 1.00" standard blocks using reduction sleeves) |
| Overall Tool Length | 250 mm | 9.8425 inches (S-Type Rigid Medium Reach) |
| Minimum Machining Bore (D-min) | 32 mm | 1.2598 inches minimum bore entry clearance limit |
| Compatible Indexable Insert | CCMT 120404 / CCMT 120408 / CCGT 120404 | CCMT 431 / CCMT 432 / CCGT 431 |
Industrial Cutting Feed & Speed Data Recommendation Table
| ISO Workpiece Material Group | Cutting Speed (Vc) Range | Recommended Feed Rate (fn) |
|---|---|---|
| Carbon / Alloy Steels (P-Class / AISI 1045) | 140 - 240 m/min | 0.10 - 0.30 mm/rev |
| Austenitic Stainless Steels (M-Class / SS304) | 90 - 160 m/min | 0.08 - 0.25 mm/rev |
| Grey & Nodular Cast Irons (K-Class / GG20) | 110 - 200 m/min | 0.12 - 0.35 mm/rev |
4. Product Application Scenarios
- Medium Internal Lathe Boring: Optimized for machining standard automotive hubs, bearing blocks, and engine coupling collars.
- Sub-Spindle Handover Cycles: Perfect tool clearance profile during automated rear-side spindle machining procedures.
- High Metal Removal in Medium Cavities: Enables machine shops to transition from small 16mm/20mm tool bodies to a much stiffer 25mm shank while utilizing cost-effective 12mm indexable edges.
5. Equipment Tooling Compatibility Matrix
- Standard 25mm Round Clamping Blocks: Direct loading interface for generic metric turret discs or integrated block stations.
- CNC Lathe Compatibility Ecosystem: Fits seamlessly into high-efficiency industrial turn stations like Haas, Doosan Lynx, Mazak, Citizen, and Hardinge setups.
- Global ISO Insert Interchangeability: Pocket configuration interfaces accurately with all global standard 80-degree positive rhombic size **1204** inserts (e.g., CCMT120404, CCMT120408, CCGT120402).
6. BEYOND Premium Carbide Grade Selection Guide
Enhance your S25S-SCLCL12 operational lifespan by coupling it with the corresponding BEYOND indexable carbide cutting grade classification:
| BEYOND Cutting Insert Grade | Coating Micro-Structure Matrix | Primary Application Strengths |
|---|---|---|
| BYM11 (CVD Grade) | Thick Double-Layer Al2O3 + TiCN Thermal Shock Barrier | High-speed continuous dry roughing of hard carbon steels, tool alloys, and mold blocks. Resists high heat. |
| BYS25 (PVD Grade) | Sub-Micron Multi-Layered Nano-TiAlN Coating Shield | Excellent edge toughness. Best for interrupted heavy cuts, tough stainless steel (SS304/316), and superalloys. |
| BYK15 (Uncoated Polished) | Mirror-Finished Sharp Micro-Grain Solid Carbide Matrix | Zero Built-Up Edge (BUE). Engineered specifically for high-speed boring of aluminum blanks, brass components, and plastics. |
7. Why Choose BEYOND CNC Machine Tools?
BEYOND delivers premium-engineered, industrial-grade indexable tool holders trusted by production facilities worldwide. By utilizing 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
Marcus V. — United States
"Outstanding tool rigidity for a 25mm alloy steel shank. We run it on our Haas lathe inside 35mm starter bores using CCMT120404 inserts. Chip evacuation is smooth and flawless."
Hans K. — Germany
"Sehr gut balanced. This left-hand bar is exactly what we needed for back-boring steps on our sub-spindle line. The insert pocket alignment is incredibly tight and repeatable."
Kenji T. — Japan
"Fits perfectly using our 1-inch block reduction sleeves. We run it with polished CCGT120404 inserts for high-speed aluminum casing cycles. Perfectly clean mirror finishes."
Matteo L. — Italy
"Solid screw locking torque. The insert pocket doesn't slip or deform even under continuous structural steel profiling loads. Great industrial product quality."
Robert S. — United Kingdom
"The 250mm tool length is perfect for our batch hydraulic bush runs. Massive metal removal rates without sacrificing tool holder lifespan."
8. AI-Style Engineering Support Engine (FAQ)
Q1: What is the absolute minimum bore entry limit for this 25mm shank boring bar?
A1: The absolute minimum machining diameter (D-min) is 32mm (approx 1.259"). Running this tool holder into a cavity smaller than 32mm will cause the lower head clearance profile to friction-rub or catastrophically crash against the internal wall.
Q2: Why choose S25S-SCLCL12 over a larger 32mm shank boring bar?
A2: The 25mm shank enables entry into narrower internal bores (down to 32mm), whereas a 32mm bar requires a 40mm minimum opening. It offers the ideal trade-off between geometric clearance and high structural rigidity.
Q3: Can I run this tool holder directly inside a 1-inch standard imperial tool block?
A3: A metric 25mm shank measures approximately 0.9842 inches. Because it is slightly smaller than a standard 1.000" imperial pocket, you must use a standard metric-to-imperial round boring bar sleeve tool holder adapter to guarantee rigid centerline clamping.
9. Technical Maintenance & Troubleshooting Guidelines
Equivalent Industry Models
Interchangeable with universal ISO metric standard S25S-SCLCL12 configurations across all global tooling suppliers. In North American machine shops, it functions as a drop-in match for 1-inch round stations using standard metric reduction tooling adapter sleeves.
Troubleshooting Tips
Vibration / Chatter Marks: Ensure the tool overhang ratio does not exceed 3x diameter (75mm maximum extension). If harmonics persist, slightly elevate your feed rate (fn) to engage the chipbreaker or decrease nose radius to 0.4mm (CCMT120404).
Pocket Wear / Lifetime Drop: Always clean out fine metal micro-dust from the pocket seat utilizing compressed air before indexing to avoid micro-misalignment issues.
Workpiece Material Matrix
Universally compatible with standard industrial metal alloy groups: P (Carbon, Structural & Pre-hardened Steel Alloys), M (Austenitic & Martensitic Stainless), K (Grey, Nodular & Ductile Cast Irons), N (Aluminum, Brass & Non-ferrous alloys), and S (Inconel, Titanium & Superalloys).
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.