SRGCL2020K12 External Turning Tool Holder for RCMT Inserts – BEYOND
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SRGCL2020K12 External Turning Toolholder
Precision 20x20mm Left-Hand Shank for RCMT1204 Round Inserts
Product Overview
"What is the best 20mm toolholder for vibration-free profiling and radius turning with round inserts?"
The Beyond SRGCL2020K12 is a professional-grade external turning toolholder designed for high-performance profiling using RCMT1204 round inserts. The 20x20mm shank provides a perfect balance of agility and rigidity for medium-sized CNC lathes. By utilizing round insert geometry, the SRGCL series offers a stronger cutting edge than traditional diamond shapes, allowing for multi-directional cutting and exceptional heat dissipation in tough-to-machine alloys.
Key Features
- ✔ High Rigidity Design: Forged from high-tensile alloy steel to suppress vibration during deep profiling.
- ✔ Screw-Down Clamping: Ensures the RCMT12 insert remains perfectly stationary under high radial loads.
- ✔ Profiling Versatility: No fixed lead angle allows for smooth radii and contouring in both directions.
Technical Specifications
Screw Clamp
Round Shape
90° Approach
7° Relief
Left Hand
20x20mm
125mm Len
RCMT12
| Technical Data | Metric (mm) | Imperial (inch) |
|---|---|---|
| Shank Size | 20 x 20 mm | 0.787" x 0.787" |
| Overall Length | 125 mm | 4.921" |
| Compatible Insert | RCMT 1204** | Round 1/2" |
Recommended Cutting Parameters
| Material Group | Cutting Speed (Vc) | Feed Rate (f) |
|---|---|---|
| Carbon Steel (P) | 150 - 230 m/min | 0.15 - 0.45 mm/rev |
| Stainless Steel (M) | 110 - 170 m/min | 0.10 - 0.35 mm/rev |
Required Insert: RCMT 1204** / RCGT 1204**
Specifically designed for 12mm round inserts for maximum profiling agility.
Shop RCMT1204 Inserts →Applications
- Complex Shaft Profiling
- Radii Turning & Contouring
- Heavy Roughing of Castings
- Semi-finishing in Stainless Steel
Compatibility
Fits all standard CNC Turrets with 20mm tool slots. Fully compatible with ISO standard RCMT/RCGT 12mm round inserts from brands like Sandvik, Mitsubishi, and Beyond.
Beyond Material Comparison
Forged Steel Shank: Our toolholders are manufactured from 42CrMo alloy steel, quenched and tempered to HRC 42-45. Compared to standard 45# carbon steel shanks found in budget alternatives, Beyond toolholders offer significantly higher impact resistance and thread durability.
Customer Field Reviews
"Great stability for profiling stainless parts. The 20mm shank fits perfectly in our HAAS turret."
— John M., USA"Halter ist sehr präzise gefertigt. RCMT1204 Platten passen spielfrei. Top Preis-Leistung."
— Dieter W., Germany"Excellent rigidity for radii turning. Much better tool life than using diamond inserts for profiling."
— Marco P., Italy"Precision manufacturing. Fits our Japanese lathe turrets perfectly."
— Kenji S., JapanFrequently Asked Questions
Can I use RCGT inserts for aluminum in this holder?
Yes! The SRGCL2020K12 is designed for both RCMT (standard) and RCGT (ground/polished) 12mm round inserts.
Is this toolholder Left-Hand or Right-Hand?
The "L" in SRGCL indicates a Left-Hand toolholder. Ensure this matches your machine's turret and spindle rotation.
Why use a round insert for profiling?
Round inserts have the strongest cutting edge and allow for multi-directional cutting without chipping, which is ideal for complex contours.
Material Pro Tip: Round vs. Diamond Profiling
While diamond inserts (CNMG/DNMG) are great for straight turning, round inserts on an SRGCL holder are superior for materials with hard skins or scales. By distributing the cutting force over a larger radius, you significantly increase tool life and process stability in interrupted cuts.
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.