4 Replies Latest reply on Sep 14, 2011 6:34 AM by Tudor Silaghi

    ISO 2768-mK

    Doug Heikamp
      Greetings all

      Can someone please tell me what the mK means? Right now I am assuming the "m" stands for medium, and I have no idea on the "K"

      Thanks in advance
      • Reply
        • ISO 2768-mK
          Steve Calvert
          Doug, there are 2 parts to ISO 2768. -1 and -2. -1 refers to tolerances for linear and angular dimensuons without tolerance indications and -2 refers to geometric tolerances for features with individual tolerance indiscations.

          So, in -2 you'll see that K is a tolerance class

          • ISO 2768-mK
            Eddie Cyganik

            Just to add to what Steve has already mentioned:

            ISO 2768-1 General Tolerances (linear & angular) has three charts, Linear, Broken Edge & Angular. Each chart is divided in four classes of tolerances as follows:
            f = fine
            m = medium
            c = coarse
            v = very coarse

            The tolerance designation is determined by various items, such as size, complexity & means of manufacture of your parts.

            ISO 2768-2 General Tolerances (geometric) has four charts, Straightness & Flatness, Perpendicularity, Symmetry and Circular Run-out. Each chart is divided into three classes of tolerances as follows: H, K and L. They are not literally defined in the specification, although I believe all letters from this specification are derived from Fit Tolerancing Charts ISO 286.

            On our metric drawings we specify ISO 2768-m K
              • ISO 2768-mK
                Doug Heikamp
                Thanks Steve and Eddie

                Thanks for the info. It is starting to become a little clearer as to what impact this standard has on the way we manufacture I would hate for us to have our work rejected because we chose to ignore the tolerances