Tube wrenches are adjustable tools used for holding and turning a pipe. It holds the tube in place because it has two serrated edges. These jaws are the main difference between a tube wrench and a normal wrench, though there are a variety of tube wrenches. Another is that the tube wrench only has a narrow opening that is only large enough for the wrench to go onto the tube. It makes it much easier to have contact on the nuts of plumbing tubes. It is used in this case because plumbing nuts are softer and get damaged easily by an open end or adjustable wrench.
A choke tube wrench is closed which helps to remove or install choke tubes by using an expanding element that fits right into the choke tube that is being changed. As it expands, it pushes against the inside of the choke tube to keep it from sliding. Outward serrated edges on the tube wrench push notches into the tube, helping to turn it. These tube wrenches were filed for patent towards the end of the year 1989. Its patent was granted a year later, in October of 1990. The creation was credited to two New York men, Stavros Mavrakis andThomas R. Cresci.
Ratchet tube wrenches are made of stainless carbon steel and can be used for hydraulics and plumbing. The jaws of this wrench are made with springs that snap open. They close in onto the tube or fitting. This allows these tube wrenches to be used in small or tight spaces. Most ratchet tube wrenches come in a variety of sizes. Some of the common sizes are 5/8, 5/16, 1/2, and 3/4 inch.
A tube nut wrench has a separated push button that alters this electrically operated wrench. It knows when there has been too much pressure set onto the tube, so it loosens its grip. It can sense when the motor is stalled for an extended period of time and shuts off. This wrench received its patent in June of 1997. The inventors were three Pennsylvania men, John M. Estep, Harry E. Morris III, and Donald R. Warner.
Most tube wrenches require that it be switched into the reverse position to loosen up the grip, but some, like the aforementioned, can be stopped without manual intervention. It can be advantageous in certain circumstances to use this type of tube wrench to eliminate the limits that non-automatic tube wrenches present.