Nails, Screws, Bolts, and Other Fasteners - Carpenter's and Builder's Math, Plans, and Specifications - page 36

wall without drilling a hole first. Very short anchors are also avail-
able for use in thin wood paneling and hollow-core flush doors.
Once they are in place, the anchors are removable only with some
ingenuity if a large hole in the wall is to be avoided. One method
that works (but must be done gently) is to replace the screw in the
anchor with another one of the same size and thread, but longer.
This replacement screw must be threaded into the anchor only one
turn (if at all). Once it is in place, smack the head of the screw with a
hammer. This action may straighten out the bent legs of the anchor
so that it can be withdrawn from the wall intact. More frequently,
it will either break off the legs or break off the flange.
Remove the screw, and in the former case, pull the flanged section
of the anchor out of the wall with the fingers (if it won't come out
all the way, pull it out as far as possible, cut it in two with diagonal
cutters, and let the stubborn half drop down inside the wall cavity).
If the flange breaks off, push the remainder of the anchor back inside
the wall. The only hole to be patched will be the one originally bored
for the anchor, although a too-vigorous hammer blow can produce
an additional dimple in the wall surface. The method is a little risky
with very soft or very thin wall facings because their relative lack of
substance may allow the flange to be driven backward through the
facing. Let good judgment be the guide. It may be better to leave the
anchor alone.
To ggle Bolts
These differ from hollow wall anchors in that they must be attached
to the object to be fastened before they are inserted into the wall. In
their larger sizes, they will carry a heavier load (see Table 1-14). In
all sizes, they are good for axial as well as radial loads, need a larger
hole for mounting, and once mounted, cannot be reused if the screw
is removed from the toggle. A longer screw is necessary in order to
allow the wings of the toggle to unfold in the wall cavity.
Toggle bolts (see Figure 1-30) are simple devices consisting of a
center-hinged crosspiece pierced in the middle by a long machine
screw. The crosspiece (called the toggle )iscomposed of two halves
(called the wings ) hinged around a threaded center through which
the screw runs. The wings are normally held at almost a right angle
to the screw by spring pressure but can be folded flat along the
screw to allow insertion into the wall. Once inside the wall cavity,
they automatically snap upright again (they fold only one way—
toward the head of the screw) and prevent removal of the unit.
Tightening the screw squeezes the toggle firmly against the inner
wall surface and the object to be fastened against the outer wall