What is a spanner wrench?

By: HowStuffWorks.com Contributors  | 
Key Takeaways
  • Spanner wrenches are tools designed to grip and turn nuts or bolts with pins or tabs around their circumference.
  • Common types include the C spanner, with an open head shaped like the letter C, and the ring spanner, which has a completely enclosed ring for a secure fit on hexagonal or square bolts.
  • Spanner wrenches are essential for plumbing and gas repair tasks since they can provide strong leverage and access in confined spaces.

A wrench is a tool that provides a grip for tightening or loosening a fastener, such as a nut or bolt. The term spanner wrench is redundant; Americans consider this kind of tool a wrench, while the British refer to this tool as a spanner. While there are many kinds of wrenches, Americans refer to the type of wrench that contains pins or tabs around its circumference as the spanner wrench. These wrenches are made of steel for strength and are often chrome-plated to protect against corrosion.

There are many types of spanner wrenches, each with a distinctly shaped hook. In addition, some spanners are multi-tools with double-sided hooks. The most common type of spanner wrench is the C spanner. Its head is open in the shape of the letter C, and its jaws are meant to correspond to the similarly sized nut. The obstruction spanner is similar to the C spanner, except its jaws are angled more steeply to enable you to reach nuts in confined spaces. The ring spanner, on the other hand, has a completely enclosed ring that fits precisely over a hexagon or square bolt. While it can take some time to correctly place the ring spanner, it provides stronger leverage than open spanners. Make sure your spanner wrench is the correct size and is sitting properly around the nut before twisting. Otherwise, it could slip from the wrench and damage the tool or injure your hand.


Spanner wrenches are often used in plumbing to help repair leaky pipes or faucets. They are smaller and lighter than pipe wrenches, allowing flexibility to work in hard-to-reach areas. In addition, they provide enough turning force to open pipe connections that have been untouched for many years. Similarly, spanner wrenches are commonly used in gas repair to open gas pipes.


Frequently Asked Questions

How do you care for and maintain spanner wrenches?
Keep spanner wrenches clean and dry to prevent rust. Occasionally oil the moving parts to ensure their smooth operation.
Are spanner wrenches interchangeable with regular wrenches?
While spanner wrenches have specific uses, especially with nuts that have holes or pins, you can often use them interchangeably with regular wrenches for standard nuts and bolts.