What are the parts of a Jenny Caliper?
The main parts of a jenny caliper include the joints (both fixed and spring), legs, adjustable point, lock nut and locating lug. Read our full guide on the parts of a jenny caliper below along with the functions of each section.
Jenny Caliper Joints
While most jenny calipers have a fixed joint, some have a spring joint.
Spring joint jenny calipers are easier to use as the distance between the legs can be adjusted more quickly and easily.
Fixed joint jenny calipers can sometimes be inaccurate if the joint becomes stiff and difficult to adjust.
The fixed joint of some calipers consists of a large screw and nut. The legs of the caliper are held in place by friction at the joint.
Jenny calipers with a spring joint have an adjusting nut and threaded rod which alters the tension of the spring and opens and closes the legs.
A jenny caliper has two legs: a curved leg and a straight leg. The straight leg is run along the side of the object while the curved leg is extended to the required distance.
The angle of the sharp point at the end of the curved leg can be adjusted to extend the measuring capacity of the caliper.
When tightened, the lock nut secures the adjustable point in any set position.
It hooks over the edge of the workpiece and provides extra support to the leg, by helping to keep the caliper in place whilst measurements are taken. The locating lug is found at the end of the straight leg of the caliper.
It hooks over the edge of the workpiece and provides extra support to the leg, by helping to keep the caliper in place whilst measurements are taken. The lugs of some jenny calipers have a notch for additional support.