Hex Keys & Allen Wrenches

Hex keys turn socket-head fasteners, which appear on everything from equipment covers to line hardware and tool assemblies. The form decides how the tool is used. Folding sets keep a full range in one body, so nothing is lost out of a bag and the housing gives a handle to pull against — usually the right choice for a truck or a pouch. Individual L-keys are cheaper to replace and the long-arm patterns reach into recessed or counterbored fasteners that a short key cannot. A ball end lets the key work at an angle off square, which is the difference between reaching a fastener and not, though it carries less torque than a straight end and should not be used to break one loose. T-handle wrenches trade compactness for real leverage and speed, and suit repetitive work on the same size. Insulated hex wrenches extend the range to energized work. SAE and metric are not interchangeable — a close-but-wrong key rounds a socket head quickly, and a rounded socket head is a much longer job than finding the right key was.