TM 55-203
pieces more firmly together. Therefore, rivet driving
from 1 inch for a 1/2-inch-diameter rivet to 1 1/2 inches
should be done systematically and new rivets driven,
for a 7/8-inch rivet. Generally, a shank must be twice the
alongside cooling rivets. Surfaces next to riveted pieces
diameter of the rivet. If the proper length of the rivet is
of metal should be coated with a rust preventive paint to
not available do not attempt to use a rivet of shorter
minimize rusting out of parts.
length, because a flat, insufficient head will be formed,
the shank may fail to fill the hole, and the rivet will
become loose. If the proper length rivet is not available,
b. Driving Methods. Rivets should be fitted squarely
select one that is longer than required and cut it to the
proper length. Do not use a rivet that is too long without
into the hole so that the hole is completely plugged. The
first cutting it to length
point of the rivet should not be bent over but should be
upset so that it fills the hole its entire length. The riveting
hammer used should be powerful enough to form a
5-18. Rivet Fitting
perfect head without rocking the hammer to work down
a. General Before any riveting is done, the parts to
the edges. The hammer should be started slowly and
be joined must be secured in correct relative positions.
applied lightly until the rivet has settled into the hole and
This is done by inserting special fitting-up bolts into
enough head has been formed to hold the rivet in the
enough rivet holes to secure the parts and the parts drawn
hole, then full pressure can be applied. To obtain tight
lightly together. These bolts should be exactly the same
rivet work, it is essential that the rivet be handled and
size as the rivets to be used and will be removed only
seated in the hole while red hot and completely driven
when rivets have been driven in the remaining holes.
before cooling. The method used to form the rivet head
Where the surfaces do not come tightly together, striking
depends upon the type of riveting machine used, but will
them with a sledge and simultaneously tightening up the
fall into one of the following categories: compression;
bolts will help to pull them close. Fitting up bolts should
succession of rapid blows; rapid blows accompanied by
be so located that the majority of the punched holes are in
rotary motion of the rivet set; combined compressive and
alinement. If not so alined, holes may be reamed.
rolling or spinning motion; and application of pressure to
an electrically heated rivet.
To drive flat-head
b. Rivet Spacing. The spacing of rivets is determined
countersunk rivets, the hammer must be held firmly in
by the particular job, type, and thickness of plate and/or
position so that it does not slip off the rivet. One way to
casting, etc. Generally, the distance between rivets,
do this is to hold the 'hammer
center to center, should not be less than three times the
diameter of the rivets; the maximum center-to-center
c. Riveting Machines. There are two general types of
distance should not exceed 6 inches for rivets of 3/4-
riveting machines, the air (pneumatic)driven riveting
inchdiameter shank or larger; and center of rivet (holes
hammer and the yoke or gap riveter.
Pneumatic
should not be less than 1 1/4 inches (for 3/4and 7/8-inch
hammers are most commonly used. The short-stroke
rivets) from the edge of the ,piece being worked, except
hammers are suitable for driving rivets of 5/8-inch
where the piece is less than 2 1/2 inches wide. When it
diameter or less, the long-stroke hammers for driving all
is, the distance from the edge of the piece to the center of
larger sizes. Other forms of riveting machines include the
the .rivet hole should be at least twice the diameter of the
portable yoke riveter; the pinch bug portable riveter; a
rivet but should not exceed eight times the thickness of
portable hammer-type yoke riveter; and stationary riveting
the plate. When the plate being worked is adjacent to
machines, such as yoke riveters, bull riveters, and
legs of angles or flanges, there should be an allowance
hydraulic riveters.
between the legs and the rivet centers of at least 3/8 inch
plus 1/2 the diameter of the rivet head.
d. Riveting in Enlarged Holes. Standard steel
working procedure requires reaming holes in surfaces to
5-19. Rivet Driving
be joined so that the holes are in perfect ,alinement. It is
not always possible to do this in freight car repair work.
a. General. Riveting should begin at one end of the
The hole in the old part may be enlarged from wear, and
piece or plate and continue around the fitting bolts which
any reaming may weaken the part. In such cases, use a
are holding the members together. Rivet along the piece
rivet which fits the smaller hole. By slanting the hammer
and do not skip from place to place, as skipping fails to
draw the parts together tightly. Hot rivets contract in
cooling
and
draw
the
5-8
Previous Page
