General Information for Stainless Steel 440C
| Material Group |
M - Stainless Steel |
| Sub-Group |
Martensitic Stainless Steel |
| Tensile Strength |
870[N/mm^2] |
| Machinability Range |
35% |
MACHINABILITY OF 440C STAINLESS STEEL
Stainless steel 440C is a martensitic stainless alloy with 18% chromium 1.20% carbon. The 'C' suffix stands for 'carbon' since it is the stainless-steel alloy with the highest carbon content in the 400 series. The high carbon content yields very high strength at the expense of poor machinability, around 35%.
440C resists corrosion in a typical domestic environment and very mild industrial environments. After heat treatment, it attains the best strength, hardness, and wear resistance relative to all the other stainless-steel alloys.
Typical components made from 440C include ball bearings, races, needle valves, pump parts, and bushings.
SUMMARY:
For general turning of Stainless Steel 440C at stable conditions use a grade with a semi hard substrate and thin CVD coating.
In case you are running at a cutting speed that is lower than 390 SFM (120 m/min), it is better to use a grade with a Semi Hard substrate and PVD coating.
For general milling, use the grade with a semi-hard substrate and thin PVD coating.
For detailed carbide grades recommendations,check the table below.
Recommended cutting speed range for turning at stable conditions is 430 - 570 [SFM] / 130 - 175 [m/min].
Recommended cutting speed range for milling with stable clamping and short over hang is 260 - 360 [SFM] / 80 - 110[m/min]
For detailed cutting speed recommendations, check the table below.
Equivalent International Designations for Stainless Steel 440C
| Standard |
Name |
| SAE |
440C |
| WNR |
1.4125 |
| DIN |
X105CrMo17 |
| ANFOR |
Z100CD17 |
Chemical Composition for Stainless Steel 440C
| Element |
Amount |
| Chromium (Cr) |
17% |
| Silicon (Si) |
1% |
| Manganese (Mn) |
1% |
| Molybdenum (Mo) |
0.75% |
| Carbon (C) |
1.1% |
Cutting Speeds Recomendations for Stainless Steel 440C
| Application |
Vc (m/min) |
Vc (SFM) |
| Turning |
130-175 |
430-570 |
| Milling |
80-110 |
260-360 |
| Parting |
50-70 |
160-230 |
| Grooving |
80-105 |
260-340 |
| Drilling |
35-50 |
110-160 |
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 Stainless Steel 440C
Grade for Milling (Indexable)
Recommended Insert Cutting Edge Geometry for Stainless Steel 440C
| Honing Size |
0.03-0.05 mm / 0.001-0.002" |
| Rake Angle |
9°-11° |
| Land Angle |
Positive |
| Land Width |
0.20-0.30 mm / 0.008-0.012" |
