Tungaloy EP 75° Rhombic Turning Inserts
Optimized Profiling Geometry | Ultra-Sharp Cutting Edges | Precision Finishing
Which insert is best for intricate 75-degree profiling with high surface quality?
The Tungaloy EP Series 75° rhombic inserts (including EPGT and EPMT) are specialty tools designed for complex profiling where standard 80° (C) or 55° (D) geometries might interfere with the workpiece. The 75-degree included angle provides a unique balance of edge strength and clearance. Utilizing the AH725 PVD grade for versatile alloy machining or the NS530 Cermet grade for mirror-like finishes, these inserts are essential for precision CNC operations. The ground-class E-tolerance (for EPGT) ensures sub-micron repeatability, while the specialized -JS and -W chipbreakers provide exceptional chip breaking even at low depths of cut (Ap) and light feeds.
Decoding Tungaloy EP Series Codes
E
75° Rhombic
P
11° Relief
G / M
Tolerance
T
Hole/Fix
04/03
I.C. Size
01/02
Thickness
02/04
Radius
75° Strategic Geometry
Unique rhombic shape designed to reach tight corners and intricate profiles that standard turning inserts cannot access.
JS Chipbreaker Technology
Optimized for small-diameter machining and finishing, ensuring chips are curled and broken even in ductile materials.
High Precision Tolerance
Available in G-class ground tolerance for high repeatability, minimizing tool offset adjustments after insert changes.
Cross-Reference: Metric vs. Imperial
| ISO Model |
ANSI Model |
I.C. Size |
Application |
| EPGT 040102L-JS |
EPGT 1.2(1)0.5L |
4.76 mm |
Fine Finishing |
| EPMT 040104-PS |
EPMT 1.2(1)1 |
4.76 mm |
General Profiling |
Suggested Machining Parameters
| Finishing (NS530 Cermet) |
Vc: 150-300 m/min | f: 0.03-0.12 mm/rev |
| Medium (AH725 Carbide) |
Vc: 80-180 m/min | f: 0.05-0.15 mm/rev |
Matching Profiling Tool Holders
Compatible with SEP-type External Holders and Internal Boring Bars
Browse Precision Profiling Holders
Target Applications
- Precision profiling in medical device components.
- Swiss-type CNC machining for small diameter shafts.
- Complex valve body and aerospace fastener turning.
- High-finish automotive interior trim molds.
Equipment Compatibility
Perfectly suited for Citizen, Star, and Tsugami Swiss-type lathes, as well as high-precision CNC lathes like DMG Mori and Mazak.
Tungaloy EP Grade Selection
| Grade |
Substrate |
Primary Workpiece |
| AH725 |
PVD Carbide |
Stainless, Steel, Superalloys |
| NS530 |
Uncoated Cermet |
Finishing Carbon/Alloy Steel |
| T9125 |
CVD Carbide |
High-speed Steel Turning |
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Global Industry Reports
⭐⭐⭐⭐⭐ "Essential for Profiling" - Giovanni R., Italy
"The 75-degree angle is exactly what we needed for our specific valve components. EPGT ground tolerance is perfect."
⭐⭐⭐⭐⭐ "Swiss-Lathe Master" - Kenji T., Japan
"Excellent results in small diameter medical screws. AH725 grade handles the toughness of stainless beautifully."
⭐⭐⭐⭐ "Mirror Finish" - Hans W., Germany
"Using the NS530 cermet for finishing. Surface Ra is consistently under 0.8. Very reliable product."
Technical FAQ
Q: When should I choose EPGT over EPMT?
A: Choose EPGT (ground) for high-precision finishing and Swiss-type lathes where tool offset repeatability is critical. Use EPMT (molded) for general profiling to save costs.
Q: Does this replace the DCMT 55-degree insert?
A: Not directly. EP 75-degree inserts are used when a 55-degree is too weak or an 80-degree is too wide for the specific geometry of the part.
Tech Tip: Vibration Control
Due to the 11° relief angle of **EP inserts**, keep tool overhang minimal. For internal profiling, use carbide boring bars to maintain the rigidity needed for a chatter-free finish. **BEYOND CNC** - Your Partner in Precision.
© Technical Document by Beyond Li - CNC Tooling Technical Director
