Manual Calipers

Usually, there are many situations where a digital caliper cannot be conveniently used �?perhaps because the jaws are not long enough to reach the work-piece. In this situation, you can use the manual calipers to perform well. The manual calipers are opened (either by being pulled open against a friction screw or having an adjustment knob unwound) until the jaws of the caliper are a gentle push-fit over the work. Then the manual calipers are transferred to either the digital calipers or steel rule and a reading made of the distance between the manual caliper’s jaws. This process can be highly accurate with care.Some manual calipers can have their offset jaws completely rotated to allow them to measure both internally and externally, while others are limited to just the one function or the other. With good care, manual calipers last for many decades and so these are good tools to pick up secondhand. (Note that many older calipers are made from mild steel and so should be oiled to prevent rust.)