Question

technician a says that the \20\ in 1/4 - 20 signifies the total number of threads the fastener has. technician b says that the \1/4\ signifies the socket size of the fastener head. who is right?
technician a
technician b
both technician a and technician b
neither technician a nor technician b

Explanation:

In the fastener designation 1/4 - 20, the "1/4" represents the nominal diameter of the fastener (usually in inches), not the socket - size of the fastener head. The "20" represents the number of threads per inch, not the total number of threads. So neither technician is correct.

Answer:

D. Neither Technician A nor Technician B