A modern pipe wrench.
|Related||wrench, plumber wrench, monkey wrench|
The pipe wrench (US), Stillson wrench or Stillsons (UK) is an adjustable wrench/spanner used for turning soft iron pipes and fittings with a rounded surface. The design of the adjustable jaw allows it to lock in the frame, such that any forward pressure on the handle tends to pull the jaws tighter together. Teeth angled in the direction of turn dig into the soft pipe. They are not intended for use on hardened steel hex nuts or other fittings because they would ruin the head; however, if a hex nut is soft enough that it becomes rounded beyond use with standard wrenches, a pipe wrench is sometimes used to break the bolt or nut free. Pipe wrenches are classified by the length of the handle; they can be available in any size from as small as 3 inches up to 48 inches or larger. They are usually made of cast steel. Today, aluminium is also used to construct the body of the wrench, while the teeth and jaw remain steel. Teeth, and jaw kits (which also contain adjustment rings and springs) can be bought to repair broken wrenches, as this is cheaper than buying a new wrench.
On 17 August 1888 the Swedish inventor Johan Petter Johansson (1853-1943) took his first patent on the adjustable pipe wrench. The Swedish Patent Office issued the patent (SE 5636) again in 1894. The idea emerged after he established his company Enköpings Mekaniska Verkstad. Back then there was no standard on nut dimensions so each time a trades man was out on a job, he needed a trolley to take a whole set of fixed pipe wrenches with him. Johan Petter Johansson invented a tool that could grip nuts of different dimensions.
Pipe wrench in different countries
In South Africa, the terms "bobbejaan spanner" and "baboon spanner" are commonly used, especially for large pipe wrenches. "Bobbejaan" is the Afrikaans term for a baboon. In Zimbabwe it was usually known by an Anglicized version of the Afrikaans name, "bobbiejohn spanner".
- Adjustable spanner
- Monkey wrench, may be used as colloquial term for pipe wrench
- Nipple wrench, a pipe wrench that grabs the interior
- Plumber wrench
- Footprint Tools