2 Replies Latest reply on May 4, 2018 2:44 PM by Christopher Estelow

    How to interpret "True" on and angular dimension

    Christopher Estelow

      I was wondering if anyone could supply their interpretation of "True" with regards to an angular dimension on a print as shown in the below image.  I believe that it means they basically want pretty much a countersink to the specified diameter all the way around both ends. I mean they could use a 60° countersink tool and cut into the part until it meets the diameters specified.  Personally I think it would be much easier if it was dimensioned as wØ1.94/1.88 x 60%%d.

       

      What are your thoughts?

       

      true.png

       

      Thanks in advance,

      Chris

        • Re: How to interpret "True" on and angular dimension
          Dan Pihlaja

          If you notice, the section is cut between the teeth.

           

          This means that the dimension doesn't actually go to the angle.  If you were to measure that dimension, in that particular section view, you would get something other than 30 degrees.   This is because, as the part moves away from the section cut it is also travelling around the diameter.

           

          I believe that this is simply a way for the draftsman to indicate that the angle dimension is specifically on the teeth.  It is like a "virtual sharp" almost.

           

          Also, I want to point out that the left side would be a 60 degree countersink tool, while the right side would be a 120 degree countersink tool.