the normal porosity layer is 3-5 mm undernearth the casting surface. if your machining had cut more than 5mm off the casting surface and you still found the porosity, that was the issue of casting process;
Pike Li
uxitech.net
If i was the foundry, it is not necessary to specify the test bar to me , i will simply cast a cast on round bar dia. 50mm, and machined it according to astm norm, and test it on tensile tester.
you dont have to be bothered
Pike Li
uxitech.net
