The Rockwell hardness tester to measure the hardness of metal measures resistance to penetration like the Brinell test, but in the Rockwell case, the depth of the impression is measured rather than the diametric area. With the Rockwell tester, the hardness is indicated directly on the scale attached to the machine.
(Redirected from Apache Nation) The Apache (/ÉËpÃ¦tÊiË/; French: [a.paÊ]) are culturally related Native American tribes from the Southwestern United States, and have traditionally lived in Eastern Arizona, Northern Mexico (Sonora and Chihuahua), New Mexico, West Texas, and Southern Colorado.
A member of a Native American people inhabiting the southwest United States and northern Mexico. Various Apache tribes offered strong resistance to encroachment on their territory in the latter half of the 19th century. Present-day Apache populations are located in Arizona, New Mexico, and Oklahoma.