General Information for Stainless Steel 425
| Material Group |
M - Stainless Steel |
| Sub-Group |
Martensitic Stainless Steel |
| Tensile Strength |
[N/mm^2] |
| Machinability Range |
35% - 90% |
Machining Stainless Steel 425
Stainless Steel 425F is a martensitic (magnetic) stainless steel alloy with 13% chromium, 0.2% carbon and a machinability rating of 55%.
The amounts of carbon (Range 0.1-1.2%) and chromium (10-15%) are the main factors that affect the machinability of martensitic stainless materials.
More carbon ==> More strength, but lower machinability and less corrosion resistance
More chromium ==> More corrosion resistance, but lower machinabilty
The suffix 'F' stands for 'FreeCut'. Stainless Steel 425 Stainless Steel 425 has increased amount of Phosphorus and Sulfur to increase the machinability and improve the chip control relative to the standard 420 (without 'F').
Due to its low carbon content Stainless Steel 425 has high toughness, and therefore it is very malleable. The main challenge to machining it (relative to other martensitic stainless alloys) is breaking the chips. Therefore, it is recommended to select a sharp cutting edge with a tight chip breaker. For this reason, inserts that are designed for ausanict stainless alloys (Such as 304 and 316) will work well also on Stainless Steel 425
Summary:
For general Turning of Stainless Steel 425 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 670 - 900 [SFM] / 205 - 275 [m/min].
Recommended cutting speed range for milling with stable clamping and short over hang is430 - 570 [SFM] / 130 - 175 [m/min]
For detailed cutting speed recomendations, check the Below Table.
Equivalent International Designations for Stainless Steel 425
Chemical Composition for Stainless Steel 425
| Element |
Amount |
| Chromium (Cr) |
13% |
| Manganese (Mn) |
1% |
| Silicon (Si) |
1% |
| Nickel (Ni) |
4% |
| Molybdenum (Mo) |
0.40-1.0% |
| Carbon (C) |
0.06% |
| Phosphorus (P) |
0.04% |
| Sulfur (S) |
0.03% |
Cutting Speeds Recomendations for Stainless Steel 425
| Application |
Vc (m/min) |
Vc (SFM) |
| Turning |
155-395 |
510-1300 |
| Milling |
95-250 |
310-820 |
| Parting |
60-160 |
200-520 |
| Grooving |
90-235 |
300-770 |
| Drilling |
45-115 |
150-380 |
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 425
Grade for Milling (Indexable)
Recommended Insert Cutting Edge Geometry for Stainless Steel 425
| 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" |
