Use a line wrench on brake lines, gas lines, or adjustable cables.
photo by Matt Wright, 2008
If you are working with any type of fitting that is in-line - such as a brake line, fuel line, or any type of cable - this line wrench can be a life saver. Standard open end wrenches may not grip the hex well enough, which can lead to stripping - a real pain in the neck!
To use a line wrench, just slip the open part of the wrench over the line, then slide it onto the hex part of the fitting.