Are the units of machining cutting speed interchangeable?

Is the Cutting Speed's unit sfm (surface feet per minute) and m/min interchangeable? Inasmuch as I noticed, based on the machinist's guide, for mild steel, sfm is 100. While another source has it that for mild steel, m/min is also 100. So is cutting speed, whether it is in sfm or m/min can be directly applied to the formula of spindle speed, RPM = (CS x 4) / Diameter?


Forgot to specify that the material of the cutting tool is carbide!

3 Answers

  • 4 weeks ago
    Favorite Answer

    I don't see how they can be interchangeable.  Meters are over 3 times the length of feet.  Could be a typo or just a difference in sources.

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  • John
    Lv 7
    4 weeks ago

    From Wikipedia.  Something is truly wrong. If it's the Machinery's Handbook I would suggest that it's PICNIC:

    >1 SFM equals 0.00508 m/s (meter per second, the SI unit of speed). 

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  • 4 weeks ago

    no, SFM and m/min are not interchangeable. Look at the sources again and find out if they are talking about the same subject. Is one  of them Per second?

    Are they talking about the same cutting tool?  Is one of them diamond?

    One of them may be wrong.

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