Machining DataSheet for

General Information:
Material GroupM - Stainless Steel
Sub-GroupMartensitic Stainless Steel
Tensile Strength870 [N/mm^2]
Machinability35%

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Machining Stainless Steel 440C

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.

Summery:

  • For general Turning of Stainless Steel 440C 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 430 - 570 [SFM] / 130 - 175 [m/min].
  • Recommended Cutting speed range for milling with stable clamping and short overhang is 260 - 360 [SFM] / 80 - 110 [m/min]
  • For detailed cutting speed recomendations, check the Below Table, or use our Speed and Feed Calculator.

    • Equivalent International Designations for Stainless Steel 440C

    Standard Name
    sae440C
    wnr1.4125
    dinX105CrMo17
    anforZ100CD17

    Chemical Composition for Stainless Steel 440C

    Element Amount
    Chromium (Cr)17%
    Carbon (C)1.1%
    Manganese (Mn)1%
    Silicon (Si)1%
    Molybdenum (Mo)0.75%

    Cutting Speeds Recomendations for Stainless Steel 440C

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

    ApplicationVc (m/min)Vc (SFM)
    Turning130-175430-570
    Milling80-110260-360
    Parting50-70160-230
    Grooving80-105260-340
    Drilling35-50110-160

    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.
    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 440C

    * 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 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"

    Learn more about carbide inserts Cutting-Edge Geometry Parameters.

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