When it comes to having the right tools for the job, no toolbox or tool corral is complete without a standard, straight, heavy-duty pipe wrench. A tool designed to grip and rotate cylindrical material appears very simple on the exterior but peel back the covers and it becomes apparent that a lot of thought went into the engineering of this tool. The pipe wrench has changed over its 140-year history, but the current design of today has remained virtually the same for the past 90 years.
Using a stationary lower jaw and a movable upper jaw known as the hook jaw (because of its shape), these hardened, serrated jaws will generate tremendous gripping force when pressure is applied to the handle. However, the unique function and design of a coil and flat spring (located quietly inside the main wrench housing) also permits the wrench to easily and quickly be removed from the pipe without loosening the wrench nut when the job is complete or when the wrench needs to be repositioned on the material. This enables an easy and continuous one-hand operation once the wrench is adjusted properly for the size of material.
Properly positioning the wrench on the material is an important part of the wrench adjustment. The proper fit will center the material between the fixed jaw and movable hook jaw but leave a very important gap between the shank of the hook jaw and the surface of the material. In essence, the threaded shank of the hook jaw should not rest on the surface of the material. This gap provides room for the hardened jaws to pivot and increase their grip on the material as additional force is applied to the handle. Since these hardened jaws play such a key role in properly gripping the material, it is important to keep the jaw serrations free of dirt and debris and replace these wrench components when the teeth of the gripping surface become worn. This eliminates the risk of slippage as increased force is applied to the handle.
Also, wrenches are available in a number of sizes, and it is important to use the proper size wrench for the job at hand. Some users have been reported to use a mechanical device commonly referred to as a “cheater” but this practice is not recommended as it can overload the wrench capacity and lead to tool failure or personal injury.
Chuck Stephens, director of service and training at RIDGID, has been with the company for 33 years.