Tungaloy JTGR3250F J740 Grooving Insert
High-Precision 2.5mm External Grooving | PVD J740 Carbide | Made in Japan
What is the best 2.5mm insert for precision grooving in heat-resistant alloys?
The Tungaloy JTGR3250F J740 is a premier indexable grooving tool specifically engineered for high-accuracy external grooving. Utilizing the high-performance J740 PVD coated carbide grade, this insert excels in machining tough materials like 304/316 stainless steel, titanium, and heat-resistant superalloys. The 2.5mm cutting width (CW) and F-type chipbreaker provide exceptional edge sharpness and chip evacuation, which is critical for preventing built-up edge (BUE) in precision CNC machining. As an authentic Japan-made grooving insert, it is the industry standard for maintaining tight tolerances and superior surface finish Ra, ensuring consistent tool life in high-demand production cycles.
Decoding the JTGR3250F Technical Nomenclature
J
Mounting
T
External
G
Grooving
R
Right Hand
3250
2.5mm Width
F
Flat/Fine
J740
PVD Grade
Technical Specs: Metric vs. Imperial Units
| ISO Parameter |
Metric Unit |
Imperial Designation |
| Cutting Width (CW) |
2.50 mm |
0.0984 inch |
| Corner Radius (RE) |
0.20 mm |
0.0078 inch |
| Model Number |
JTGR3250F |
JTGR 3.098F |
| Seat Size |
3 |
Series 3 |
Recommended Cutting Parameters (J740 Grade)
-
Cutting Speed (Vc): 40 - 140 m/min (Highly dependent on material group)
-
Feed Rate (f): 0.03 - 0.13 mm/rev (Optimize for 2.5mm stability)
-
Coolant: High-pressure coolant is highly recommended for 2.5mm slots.
*Pro Tip: For 2.50mm precision grooving, ensure tool center height is aligned perfectly to prevent rubbing. J740 provides high toughness for interrupted grooving cycles.*
Global Verified Customer Reviews
⭐⭐⭐⭐⭐ "Standard for 2.5mm Grooves" - Matthias S., Germany
"The JTGR3250F J740 is our absolute standard for hydraulic components. Consistent tool life and very stable width bottom."
⭐⭐⭐⭐⭐ "Perfect for Stainless 316" - J. Rossi, Italy
"Handles tough stainless with ease. No smearing on the material, just clean and shiny grooves. PVD coating is top tier."
⭐⭐⭐⭐ "Great for Aerospace Parts" - David L., USA
"Used on Swiss machines for Inconel. The J740 grade handles heat much better than other brands I've tested."
⭐⭐⭐⭐⭐ "Quality Made in Japan" - T. Nguyen, Vietnam
"Authentic Tungaloy quality. Maintains precision even after long shifts. Highly recommended for CNC production."
⭐⭐⭐⭐⭐ "Reliable Performance" - S. Clarke, UK
"Fast shipping and genuine product. The F breaker geometry is perfect for maintaining low cutting forces and chip control."
Technical Tooling Q&A
Q: Is JTGR3250F suitable for parting-off?
A: This is specifically an external grooving insert. While it can perform light parting-off on small diameter stock, its flat geometry (F) is best optimized for precision grooves.
Q: Which tool holder do I need for this 2.5mm insert?
A: It is designed for Tungaloy J-Series external holders, such as the JCTEL/R series. Ensure you match the seat size for Series 3 inserts.
Q: Why choose J740 over CVD grades for grooving?
A: J740 (PVD) provides a sharper cutting edge and higher toughness, which is critical for precision grooving where vibration is more likely than in heavy CVD turning.
Expert Insight: PVD Coating Advantage
In precision machining, J740 represents the peak of edge toughness. While CVD coatings are optimized for high-volume steel roughing, J740 provides the sharp stability needed for the narrow slotting cycles of CNC grooving. Protect your indexable grooving tool with filtered coolant.
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