Nnwale ọkpọkọ ike n'ịntanetị akpaaka
Aerospace engine pipe hardness oru ngo n'ịntanetị na-eji ihe nnwale ike ike Rockwell akpaka anyị.
Ihe nleba anya siri ike Rockwell, onye nyocha ike ike Brinell, onye nyocha ike ike Vickers
Okwu ndị ahịa
