Yeah that's pretty clear to me as well - actually as soon as I saw the numbers! I was looking for reasons why to give to my customer. they now accept such. They did experience porosity, but I now suspect that grain from the "solidication conditions" (As TVP stated) is a major reason.
Thanks...
Corypad - The thread forming torque is varying from 1.6 to 13Nm. The 1.6 value is abnormally low. The strip torque also varies, but not as much. There is so much variation that the -3 sigma values are negative, despite testing 30 pieces (which in my experience has always been enough for...
The holes in the ignots were drilled. I am awaiting an answer on the sizing - from the pics in the report the size appears to be 8" x 24" (200mm x 500mm), but it is not entirely clear and the piece may have been cut from a bigger ignot. Thickness and casting process is unknown at this point...
I have a customer testing thread rolling and machine screws in aluminum ingots and getting lots of variability in the results. They reported that prior tests conducted in castings (engine blocks) worked well. The material is the same.
Materials are ADC10 (no heat treatment) ADC10-T5 and...
