Pipe wrenches are important tools for construction workers and plumbers, and they come in many different sizes and shapes. They are often referred to as gas wrenches, monkey wrenches, or stillson wrenches. These terms are frequently used interchangeably, but they have slight differences in their applications. The term "gas wrench" is typically used for heavy-duty pipe wrenches that are used for working with gas pipes. "Monkey wrench" was a term originally coined by the Coes Wrench Company, and it referred to a type of adjustable wrench that could be used on various sizes of nuts and bolts. Stillson wrenches are a type of pipe wrench that is especially good for gripping and turning pipes without causing damage.