Tensile Specimen

thingiverse

This specimen fits into the tensile tester component of the GUNT 300 testing machine, routinely used for testing tensile strength for materials such as aluminum, brass, copper & steel. I wanted to test out a new nylon carbon printer so I designed this specimen to match the specimens that can be obtained from GUNT for use with their machine. The shaft in the center is 6mm in diameter, and just over 30mm long (32.8mm to be exact) before the fillet leading to the screw threads on either end. I have provided the Solidworks file as well as the stl, so that you may modify the width to accommodate for tolerances or shrinkage, depending on the material of the print. Thread pitch is 1.6mm. Thread is an equilateral triangle of .85mm per side (approx .542mm in height). Check file for additional dimensions. Not responsible if you jam up your tester, experiment at your discretion. Printing vertically will yield the prettiest print, and I printed with no rafts or supports and get a nice fit with the testing machine. That being said, vertical print would not be as strong as a horizontal print, but all my prints done horizontal with rafts have come out like crap. Maybe with the proper finishing tools a horizontal print could be cleaned up. I successfully printed on PLA with the same method, vertical, 0.1mm layer height, no raft or support.