Which option correctly pairs the Rockwell B and Rockwell C indenters with their respective loads?

Which option correctly pairs the Rockwell B and Rockwell C indenters with their respective loads?

• A. 2 mm ball with 100 kg; cone indenter with 150 kg
• B. cone indenter with 150 kg; 2 mm ball with 100 kg
• C. 1/8 inch ball with 60 kg; diamond indenter with 200 kg
• D. 2 mm ball with 60 kg; cone indenter with 100 kg

Answer: (A)

Rockwell hardness testing uses different indenters and loads for different scales. The Rockwell B scale uses a spherical ball indenter with a major load of 100 kg, while the Rockwell C scale uses a diamond cone (conical) indenter with a 150 kg major load. The correct pairing matches these two standards: a ball indenter with 100 kg for the B scale, and a cone/diamond indenter with 150 kg for the C scale. The other options mix up either the indenter type or the major load, which is why they aren’t correct.

Rockwell hardness testing uses different indenters and loads for different scales. The Rockwell B scale uses a spherical ball indenter with a major load of 100 kg, while the Rockwell C scale uses a diamond cone (conical) indenter with a 150 kg major load. The correct pairing matches these two standards: a ball indenter with 100 kg for the B scale, and a cone/diamond indenter with 150 kg for the C scale. The other options mix up either the indenter type or the major load, which is why they aren’t correct.