Thread Failure in Aluminum Casting

[Pedee68]

What the common failure modes for an aluminum casting where threads fail during assembly of bolt. The failure is stripped threads causing the bolt to not engage during assembly. Casting is A304 alloy with threads for M5 bolt. The torque value is 5.5 Nm.

Looking for areas to investigate either the casting, bolt or torque process.

 

[GregLocock]

Nope! I was in vehicle development, not design for most of my career. I was design engineer on alloy wheels for a brief while, but they use fancy nuts not threads.