If a material has a Brinell hardness number of 100, what will happen during a file test?

If a material has a Brinell hardness number of 100, what will happen during a file test?

• A. File will bite in slowly
• B. File will bite in easily
• C. File will not bite at all
• D. File will spark

Answer: (B)

Hardness determines whether a cutting tool can remove material. A Brinell hardness number of 100 means the material is relatively soft for metal standards, so the teeth of a file can easily bite into it and shave material away. In a file test, a soft material will yield to the filing action, leaving scratches and noticeable cutting action as the file teeth cut through. If the material were harder than the file, the file would skate or barely bite at all, showing little to no material removal. Sparking is not a typical result of a simple file test and would indicate grinding or high-energy abrasion, not normal filing. So the material at 100 HB will allow the file to bite in easily.

Hardness determines whether a cutting tool can remove material. A Brinell hardness number of 100 means the material is relatively soft for metal standards, so the teeth of a file can easily bite into it and shave material away. In a file test, a soft material will yield to the filing action, leaving scratches and noticeable cutting action as the file teeth cut through. If the material were harder than the file, the file would skate or barely bite at all, showing little to no material removal. Sparking is not a typical result of a simple file test and would indicate grinding or high-energy abrasion, not normal filing. So the material at 100 HB will allow the file to bite in easily.