TECHNICAL NOTE NUMBER 164
UNITED STATES DEPARTMENT OF AGRICULTURE FOREST SERVICE
FOREST PRODUCTS LABOATORY
MADISON 5, WISCONSIN R ,,S 16MET L 93
COMMON STYLES OF NAILE -W
There are seven styles of nailed-wood boxes so universally used that
they may be called the standard styles. These boxes can be adapted to
a wide range of uses, and it is the experience of the Forest Products
Laboratory that they are the most efficient of the nailed-wood boxes.
Some of the advantages and disadvantages of each style, as revealed in
laboratory tests and by observation of boxes in service, are given in the
In style 1, the grain of the end and sideboards runs approximately paral-
lel to the top and bottom surfaces of the box. Since the strength of wood
in tension across the grain is not great, one of the common causes of
failure in this style of box is the tendency of the ends and sides to split
along the grain. Another common cause of failure is the low holding
power of nails driven into the end grain of the wood.
The disadvantages of style 1 may be corrected by nailing rectangular or
triangular corner cleats to the inside of the ends, as shown in style 5.
These cleats help prevent the ends and sides from splitting without in-
creasing the outside dimensions or displacement of the box. If the cleats
are made large enough, the side boards as well as the end boards may
be nailed to them, thus increasing the strength of the nailing at this point.
The inside cleats should be shorter than the inside depth of the box, so
that, if the sides and ends shrink, the cleats will not force open the joints
at the top and bottom of the box. In all boxes with cleated ends, the nails
holding the cleats to the ends should be long enough to permit a good
clinch and should be spaced approximately the same as the nails in the
adjacent edges ot the box.
The most common method of preventing box ends from splitting and of
supplementing the holding power of nails driven into the end grain is the
addition of two outside cleats on each end, as shown in style 4. These
cleats should be of the same thickness as the end boards, so that the
same-size nail can be used to fasten the sides to the ends and cleats as
is used to fasten the top and bottom to the ends. The side nails should
be alternately driven into the ends and cleats. This staggered nailing
permits a closer spacing of the nails and results in a stronger joint than
that obtained by driving the nails in a single row. The holding power of
the nails may be substantiallyincreased byusing woods of greater dens-
ity for the ends and cleats.
The cleats in the style 4 boxes should not come flushwith the outer sur-
face of the topand bottombut should have clearance of from 1/8 to 3/16
inch at each end of the cleat. They will thus helpkeep the top and bottom
in place and will absorb some of the thrust normally taken by the nails
when the box is dropped on a corner. If the cleats are made flush with
the outer surfaces of the top and bottom, subsequent shrinkage could
cause the cleats to project, so that theymight bepulled loose inhandling.
The two horizontal cleats in styles 2, 2-1/2, and 3 permit a staggered
nailing pattern to be used for fastening the tops and bottoms to the ends
and cleats as well as for fastening the sides to the ends and cleats. The
additional holding power of the nails and the stronger end construction
make these styles adaptable for heavy, difficult loads. Failure in these
boxes may be caused bynails pullingoutof the ends and cleats or shear-
ing out at the ends of the side, top, and bottom boards or by splitting of
the end boards along the inner edges of the horizontal cleats.
Styles 2 and 2-1/2 have an advantage over style 3 in that it is possible
to place more nails near the top and bottom edges of those boxes when
nailing the vertical cleats than it is when nailing the mitered corners of
the style 3 box. Style 2-1/2 has an additional advantage in that, when
the top and bottom are being nailed to the cleats, the notches in the ver-
tical cleats will absorb some of the thrust that would otherwise be taken
by the nails holding the horizontal cleats. This thrust can be severe
when the boxes are assembled in a nailing machine where several nails
are driven into the cleat at the same time. Style 3 is advantageous when
manufacturing boxes with square ends because the four cleats are of the
same length and thus are interchangeable.
The style 6 box has sides and ends joined together by a series of inter-
locking tenons held together by glue. The top and bottom of the box are
usually nailed to the ends. If properly glued, the lock corners give a
more rigid box than do nailed corners. Tests show that some of the
common failures in lock-corner boxes occur because the ends and sides
split, the nails pull from or split the edges of the ends, the locks open,
or the matched joints lack sufficient strength. Experience has shown
that adequate performance of this container is largely dependent upon
good gluing and proper manufacture.
Agrcu Iture-Had son
SZ L: 423o5 F
UNIVERSITY OF FLORIDA
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