The 'blade' is the technical term for the part of the tape measure that has the markings on it. It can be either metal or flexible as we saw when we looked at the pocket tapes and surveyor's tapes and can carry either imperial, metric or dual markings. In this section we're going to look at some basic terminology about tape measure blades:
All self retracting pocket tapes have some form of blade locking mechanism. This holds the blade in the extended position so that measuring and marking out can be done without having to anchor the end of the tape. Our blade locking mechanisms come in two basic types:
The lock is put on by hand when the blade is extended to the right length. When released the blade automatically recoils back into the casing.
The lock is automatically activated when the blade is extended to the right length. When released the blade automatically recoils back into the casing.
In addition to the locking mechanisms mentioned above there are pause buttons. Pause buttons simply hold the blade at the extended length as long as they are held down. Releasing the button triggers recoil.