New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What type of finish does the commonly used steel pipe known as black iron pipe have?

1. Galvanized coating

2. Lacquer coating

3. Painted finish

4. Rough finish

The correct answer is: Lacquer coating

Black iron pipe is specifically recognized for its distinctive finish, which is a result of the manufacturing process. The surface of black iron pipe is bare steel, which is uncoated, giving it a dark, oxidized appearance. This finish is often referred to as "black" due to the iron oxide formed during production. It's important to note that the finish on black iron pipe is not lacquer, painted, or galvanized. A lacquer coating would imply a layer of protective finish applied to the surface, which is not characteristic of black iron pipe. Similarly, a painted finish would require an additional layer of paint, while galvanized coating involves a zinc covering that provides rust protection, neither of which apply to black iron pipe by default. The rough finish option could imply a textured or unrefined surface that is not the primary characteristic of black iron pipe. Instead, its unadorned finish is critical for compatibility with various fittings and joints in plumbing applications.