2 Replies Latest reply on May 28, 2014 4:36 AM by Keith Parker

    Creating Grade 8 Bolt

    Alexander Drechsel

      Hello Everyone,


      I see there is a list of hex head bolts in the design library, but I do not see grades.  I am assuming since there is no material tied to the bolt that that would be the determining factor of the grade.  Does this sound correct?  If not, please feel free to help. 

        • Re: Creating Grade 8 Bolt
          Jerry Steiger



          I believe you are correct.


          Jerry S.


          PS. You should listen to Keith on this subject. When I said that I thought you were correct in thinking that the material determined the grade of the bolt, I was including the material processing as part of the "material". So a heat treated piece of steel is not the same "material" as an annealed piece of the same type of steel. The tie-in to the "material" is not so clear when it comes to other types of processing. A machined thread does not have the same strength as a rolled thread in the same material.

          • Re: Creating Grade 8 Bolt
            Keith Parker

            Hi Alexander.  Sorry - this is going to sound a bit overbearing, but if you're assuming that the material has a determining factor in the grade of the bolt, you're in the wrong business or maybe you're a student.  The grade of the bolt is governed by the material and that material's heat treatment and finish.  A 'Grade 8' bolt can have many sub-grades; for example a Grade 8.8 bolt is made from steel that has a nominal theoretical ultimate tensile strength of 800MPa and a theoretical yield strength of 0.8 x 800MPa (i.e. 640MPa).  The actual strength of a bolt-and-nut combination is determined by many factors (insertion length, thread quality, thread form, etc).  So be careful - the Design Library gives you a MODEL of a bolt, not a bolt that you can use to obtain mechanical properties of a bolted joint, etc.


            All the best, Keith