USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 3/TASK 1
usually available in 3 inch sizes, although larger size calipers are made.
The standard 3 inch slide caliper will measure from 0 to about 2 inches
outside, and from 1/8 inch to a little more than 2 inches inside.
caliper shown has a mark or graduation line on the fixed jaw, which enables
the user to read the inside measure, while the outside measure can be read
directly from the inner edge of the fixed jaw. If these marks were not on
the slide caliper, it would be necessary to add the thickness of the nibs to
the reading when using it as an inside caliper.
All slide calipers are
equipped with a locking device which makes it possible to hold the jaws in
any desired position. On the other side of the instrument is an ordinary
c. Use of Dividers. In setting a divider to a dimension on a scale,
the usual procedure is to locate one point in one of the inch graduations of
the rule and to adjust the nut or screw so that the other point falls easily
into the correct graduation (figure 179, view A, on the following page).
Make sure certain points of the divider are not blunt (figure 179, view B).
Do not set to the end of a rule.
When transferring a dimension from a part or tool to the scale on a rule,
use the same care in adjusting the points of the dividers, making sure there
is no pressure tending to spring the points either in or out. Illustrated
in figure 179, view C, is a mechanic scribing a radius on a die block he is
laying out. It will be seen that no pressure is being applied to the legs
of the dividers.
d. Use of Calipers.
Either the caliper is set to the dimension of the work and the dimension