Beyond KGMR2020K-3T20 External Grooving Tool Holder for GMM3020 Inserts
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BEYOND KGMR2020K-3T20 External Grooving Holder
Precision Parting and Shallow Grooving Solution for CNC Lathes
Product Overview
The BEYOND KGMR2020K-3T20 is a specialized external grooving and parting tool holder designed for maximum rigidity. Utilizing high-strength alloy steel with a professional-grade quenching process, this holder is engineered to hold GMM series inserts (specifically 3mm width). The unique clamping mechanism ensures that even under heavy side loads during grooving, the insert remains perfectly seated, preventing edge chipping and improving surface finish.
Key Performance Features
- ✔ High Rigidity Shank: 20x20mm dimensions provide the mass necessary to dampen harmonic vibrations during parting.
- ✔ Superior Clamping Force: Top-press screw design ensures the insert doesn't move during intermittent cutting.
- ✔ Advanced Surface Coating: The holder body features a corrosion-resistant black oxide finish for long tool life in wet environments.
Nomenclature Decoding (How to Read KGMR)
Clamping Type
Grooving
External
Right Hand
20x20mm
125mm Length
Insert Width
Max Depth
| Parameter | Metric (ISO) | Imperial (ANSI) |
|---|---|---|
| Shank Size | 20 x 20 mm | 0.787 x 0.787 in |
| Total Length | 125 mm | 4.921 in |
| Groove Width | 3.0 mm | 0.118 in |
| Max Depth (T-max) | 20 mm | 0.787 in |
Recommended Cutting Parameters
| Workpiece Material | Cutting Speed (Vc) | Feed (f) |
|---|---|---|
| Carbon Steel | 120 - 180 m/min | 0.10 - 0.20 mm/rev |
| Stainless Steel | 80 - 140 m/min | 0.08 - 0.15 mm/rev |
Primary Applications
- External grooving for shafts and rollers.
- Parting-off operations for bar stock up to 40mm diameter.
- Profile grooving in steel, stainless, and aluminum.
- Ideal for medium to high-speed CNC turning centers.
Device Compatibility
- CNC Lathes (Turret and Gang Tooling).
- Conventional Lathes with 20mm Tool Posts.
- Automatic Screw Machines.
BEYOND Holder Material Comparison
| Series | Material Base | Performance Advantage |
|---|---|---|
| KGMR (Professional) | 42CrMo Alloy Steel | High Impact Resistance & Fatigue Strength |
| Standard Series | C45 Steel | Economical, General Turning Only |
Trusted by Machinists Globally
⭐⭐⭐⭐⭐
"The KGMR2020 is rock solid. Parting 304 stainless was a breeze with no chatter."
— David S., USA 🇺🇸⭐⭐⭐⭐⭐
"Preis-Leistung ist unschlagbar. Sehr passgenau für GMM Einsätze."
— Hans W., Germany 🇩🇪⭐⭐⭐⭐⭐
"Holders from BEYOND are always reliable. Great surface finish."
— Fabio R., Italy 🇮🇹⭐⭐⭐⭐⭐
"Very fast delivery to Tokyo. Tool fits perfectly."
— Kenji A., Japan 🇯🇵Frequently Asked Questions
Q: What insert width does the -3T20 indicate?
A: The "3" indicates a groove width of 3.0mm, and "T20" means the maximum cutting depth (groove depth) is 20mm.
Q: Does this holder include the inserts?
A: No, this is the tool holder only. It includes the wrench and clamping screws. Inserts must be purchased separately.
Q: Is this a right-hand or left-hand tool?
A: The "R" in KGMR signifies a Right-Hand orientation, which is standard for most external turning turret setups.
Professional Tip: When using the KGMR for parting off, always ensure the tool is set exactly to the center height of the workpiece to prevent nub formation and premature insert failure.
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.