Question

the _____ file cleans clogged or distorted threads on bolts and studs
○ a. rough
○ b. thread
○ c. course bastard
○ d. second cut

Explanation:

A thread file is specifically designed to clean clogged or distorted threads on bolts and studs. Other types of files like rough, course bastard, or second cut files have different primary uses such as general material removal or finishing surfaces rather than thread - related cleaning.

Answer:

B. Thread