Machining DataSheet for

General Information:
Material GroupM - Stainless Steel
Sub-GroupFerritic Stainless Steel
Hardness42.5 HRC
Tensile Strength1000-1800 [N/mm^2]
Machinability48%

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Machining Stainless Steel 440A

Stainless Steel 440A is a ferritic (Magnetic) stainless steel alloy with 17% chromium, 0.1% carbon and a machinability rating of 48%.

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

    • Due to its low carbon content Stainless Steel 440A 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 440A

    Summery:

  • For general Turning of Stainless Steel 440A at stable conditions use a grade with a Semi Hard substrate and 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 a grade with a Semi Hard substrate and PVD coating.
  • For detailed carbide grades recommendations, check the Below Chart, or use the Grades Wizrad.
  • Recommended Cutting speed range for turning at stable conditions is 590 - 790 [SFM] / 180 - 240 [m/min].
  • Recommended Cutting speed range for milling with stable clamping and short overhang is 360 - 490 [SFM] / 110 - 150 [m/min]
  • For detailed cutting speed recomendations, check the Below Table, or use our Speed and Feed Calculator.

    • Equivalent International Designations for Stainless Steel 440A

    Standard Name
    sae440A
    wnr1.4109
    dinX70CrMo15
    unsUNS S44002

    Chemical Composition for Stainless Steel 440A

    Element Amount
    Iron (Fe)81%
    Chromium (Cr)17%
    Silicon (Si)1%
    Manganese (Mn)1%
    Molybdenum (Mo)0.75%
    Nickel (Ni)0.5%
    Carbon (C)0.07%
    Phosphorus (P)0.04%
    Sulfur (S)0.03%

    Cutting Speeds Recomendations for Stainless Steel 440A

    * Click on the speeds below for higher precision in specific conditions!

    ApplicationVc (m/min)Vc (SFM)
    Turning180-240590-790
    Milling110-150360-490
    Parting70-95230-310
    Grooving105-145340-480
    Drilling50-70160-230

    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.
    Click on the speeds in the above table to get better precision for specific parameters
    Or use our Speed and Feed Calculator


    Recommended Carbide Grades for Stainless Steel 440A

    * If you do nott understand the below table? Read This Explanation to make the most out of it!

    Grade for Turning

    Grade for Parting Off

    Grade for Grooving

    Grade for Milling (Indexable)

    Recommended Insert Cutting Edge Geometry for Stainless Steel 440A

    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"

    Learn more about carbide inserts Cutting-Edge Geometry Parameters.

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