[EricVanWyk]

I just finished conversing with our Wurth rep. He send me a small ppt with the appropriate specs. I can email it to you if you'd like. Unfortunately, it is pictures of text with bad compression...

Summary:

Max Torque 3.9 Nm -
Break torque 10 Nm - Destruction of threaded shank
Break Torque 25 Nm - Destruction of the press-fit pins


Upon seeing the photos, his immediate response was that you probably used a 1/4-20 nut instead of an M6 and then cranked it. I'm not sure what the root cause is, but we can swing this as a reminder to all teams:

Only use M6 nuts on the PD Shanks.
Don't force any connectors.


More Info just received (in new legible text format!!):

Mechanical properties (reference values):
Material: CuZn39Pb3
Shear-off force: 350 N/mm²
Tensile force: 480 N/mm²
Tensile yield strength : 340 N/mm²
Elongation: 20%
E-Module: 96 kN/mm²
Torsion-Module: 32 kN/mm² (shear modulus)