What does NCD stand for?

What does NCD stand for?

• A. Bolt circle Diameter
• B. Nominal Circle Diameter
• C. Bolt Circle Distance
• D. Neck Circumference Diameter

Answer: (A)

NCD refers to the size of the bolt pattern: the diameter of the circle that passes through the centers of all the bolts in the pattern. This bolt circle diameter is what you use to determine whether parts with matching bolt patterns will line up correctly, since it fixes how far apart the bolts sit around the circumference. The other terms don’t describe the bolt-hole layout the same way—one would imply a general circle size not tied to bolt holes, another would refer to a linear distance between holes, and a nonstandard term about neck measurements isn’t related to bolt patterns. So the bolt circle diameter is the correct meaning here.