Tensile Specimen

thingiverse

This specimen fits perfectly into the tensile tester component of the GUNT 300 testing machine, which is commonly used to test the tensile strength of materials like aluminum, brass, copper and steel. I designed this specimen to match the ones that can be obtained from GUNT for use with their machine. The central shaft has a diameter of 6mm and a length of approximately 30mm (32.8mm to be precise), followed by a fillet leading up to the screw threads on either end. I've included both the Solidworks file and STL so you can modify the width to accommodate for tolerances or shrinkage, depending on the material used in the print. The thread pitch is 1.6mm and features an equilateral triangle with sides of approximately 0.85mm (or about 0.542mm in height). For additional dimensions, please check the file itself. I'm not responsible if you jam up your tester; use at your own discretion. Printing vertically yields a very neat print, and I achieved this using no rafts or supports while printing with PLA. While vertical prints may not be as strong as horizontal ones, all my horizontal prints done with rafts have turned out poorly. Maybe with the right finishing tools, horizontal prints could be salvaged.