Select the group of thread which belongs in the NC thread category.

Select the group of thread which belongs in the NC thread category.

• A. 12-24, 1/2-13, 10-24
• B. 8-32, 3/8-24, 1/4-20
• C. 6-32, 1-12, 5-40
• D. 4-40, 3/16-24, 1/8-22

Answer: (A)

NC threads refer to the coarse-threaded form of the Unified Thread Standard used for general-purpose fastening. They have a larger pitch (fewer threads per inch) than the fine-thread series. The group shown contains thread sizes that are the coarse-pitch choices for their respective diameters, aligning with the NC (National Coarse) category. The other groups mix fine or mixed thread pitches (such as finer UNF options), which do not fit the NC classification as a whole.

NC threads refer to the coarse-threaded form of the Unified Thread Standard used for general-purpose fastening. They have a larger pitch (fewer threads per inch) than the fine-thread series.

The group shown contains thread sizes that are the coarse-pitch choices for their respective diameters, aligning with the NC (National Coarse) category. The other groups mix fine or mixed thread pitches (such as finer UNF options), which do not fit the NC classification as a whole.