General Information for Material Inconel 718
| Material Group |
S - Superalloys (Heat resistant and Titanium) |
| Sub-Group |
Superalloy |
| Hardness |
42.0 HRC |
| Tensile Strength |
1330 [N/mm^2] |
| Machinability Range |
10% |
MACHINABILITY OF INCONEL 718 MATERIAL
Inconel 718 is a nickel-based heat resistant superalloy (HRSA) material with a machinability rating of 10% and hardness of 42 HRC.
It has 54% nickel and additional alloying elements per the table below.
Inconel 718 is the most widely used heat resistance superalloy (HRSA) due to its high strength over a vast temperature range. It can be used in environments from sub-zero up to 1300°F/704°C. Throughout this entire range, it exhibits exceptionally high yield, tensile and creep-rupture properties. It is often encountered in jet-engine components, turbochargers, and heat-exchangers.
It should be machined with positive and sharp cutting edges. Geometries that are suitable for austenitic stainless steel will also work well on HRSA. However, quality manufacturers will have different geometries specifically designed for nickel-based alloys in their catalogs.
SUMMARY:
For general turning of material Inconel 718 at stable conditions use a grade with a very hard substrate and thin PVD coating.
For general milling use a grade with a semi hard substrate and PVD coating.
For detailed carbide grades recommendations, check the table below
Recommended cutting speed range for turning at stable conditions is 110 - 150 [SFM] / 35 - 45 [m/min].
Consider using CBN inserts. Although they cost more than twice, they enable increasing the cutting speed by 2-4 times (relative to carbide).
Recommended cutting speed range for milling with stable clamping and short overhang is 80 - 110 [SFM] / 25 - 35 [m/min].
For detailed cutting speed recommendations, check the table below
Equivalent International Designations for Material Inconel 718
| Standard |
Name |
| SAE |
5383 |
| WNR |
2.4668 |
| DIN |
NiCr19Fe19NbMo |
| BS |
HR8 |
| UNS |
UNS N07718 |
| ANFOR |
NC19FeNb |
Chemical Composition for Material Inconel 718
| Element |
Amount |
| Nickel (Ni) |
54% |
| Carbon (C) |
0.02% |
| Iron (Fe) |
18.0% |
| Chromium (Cr) |
18% |
| Titanium (Ti) |
0.9% |
| Molybdenum (Mo) |
3.1% |
| Aluminum (Al) |
0.5 |
Cutting Speeds Recomendations for Material Inconel 718
| Application |
Vc (m/min) |
Vc (SFM) |
| Turning |
35-50 |
110-160 |
| Milling |
25-35 |
80-110 |
| Parting |
20-30 |
70-100 |
| Grooving |
30-40 |
100-130 |
| Drilling |
30-40 |
100-130 |
Important! The speed estimation is given for an ideal situation:
- Most suitable carbide grade
- Stable tool clamping
- Stable workpiece clamping
- Good quality raw material
- A short overhang of the cutting tool.
- Nominal hardness of the material.
- etc.
Recommended Carbide Grades for Material Inconel 718
Grade for Milling (Indexable)
Recommended Insert Cutting Edge Geometry for Material Inconel 718
| Honing Size |
0.02-0.05 mm / 0.001-0.002" |
| Rake Angle |
13° -18° |
| Land Angle |
Neutral |
| Land Width |
0.10-0.20 mm / 0.004-0.008" |
| Ground Insert |
Recommended |
