Which of the following is NOT an example of a fitting used when repairing steel pipe?

The answer is based on the definition and function of various tools and fittings in the context of repairing steel pipes. Pipe wrenches are tools specifically designed for gripping and turning pipes, not fittings used in the repair process itself. They are utilized to loosen or tighten joints, which is a crucial part of pipe work, but they do not serve as fittings that are integrated into the pipe system.

On the other hand, clamps, service saddles, and split sleeves are all fittings directly involved in the repair of steel pipes. Clamps can provide support and seal leaks, service saddles are used for connecting service lines to existing pipes, and split sleeves are often employed to provide a repair for damaged sections of pipes. Each of these fittings addresses specific repair needs within the pipeline system, making them essential components in the repairing process.