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Perforated Harboard
PERFORATED
HARDBOARD
Pegboard
Its Hook-Hanging Strength
by R.M. Granum
and O. B. Eustis Corporate Headquarters
Panel Processing, Inc.
120 North Industrial Highway
Alpena, MI 49707-0457
Phone:
(989) 356-9007
Fax:
(989) 356-9000
Customer Service:
(800) 433-7142
Panel Processing of Texas, Inc.
1010 South Bolton St.
Jacksonville, TX 75766-0871
Phone:
(903)586-2423
Fax:
(903)586-5715
Customer Service:
(800) 333-0340
Panel Processing of Coldwater, Inc.
681 Race St.
Coldwater, MI 49036-2121
Phone:
(517)279-8051
Fax:
(517)278-7148
Customer Service:
(800) 433-7142
Panel Processing of Indiana, Inc.
9250 South Mississippi St.
Merrillville, IN 46410
Phone:
(219)736-0330
Fax:
(219)738-2136
Customer Service:
(800) 621-1526
Copyright © 1999 Panel Processing, Inc.
http://www.panel.com E-mail: ppi@panel.com PERFORATED HARDBOARD
Pegboard
Its Hook-Hanging Strength
by R.M. Granum and O. B. Eustis
The attractiveness of a store fixture installation is sometimes marred by pegboard with paint-
chipped or wallowed out holes. In extreme cases pegboard may become further disfigured when
over-loaded hooks tear pieces out of the panels.
As a supplier of pegboard, we share the concerns of the store owner, the store fixture manu-
facturer and the pegboard hook manufacturer; we all want fixtures which give good service and
remain attractive for at least ten years.
Why would a pegboard installation give unsatisfactory service? Was the pegboard strength
substandard? Were the hooks poorly designed? Did the fixture frame not provide adequate sup-
port? Was the fixture loaded
beyond reasonable capacity
in the store?
In an effort to answer
some of these questions we
designed a series of tests to
determine the behavior of
various types of pegboard
and pegboard hooks under
very heavy loading.
We selected twelve types
of hooks for testing, aiming
to get a wide variety of
hooks designed to carry medi-
um to heavy loads. Then we built a test frame, shown in Figure 1, to simulate a common type of
store fixture frame, The frame provided vertical, 1/4 deep channel support for panels 47 wide
by 48 high. Bottom to bottom distance between the channels was 47-1/16.
Three types of hardboard were chosen for testing which we broadly classified as
(1)
Medium-strength 1/4; (2) High-strength 3/16; and (3) High-strength 1/4.
Then each of the twelve types of hooks was tested with each of the three types of pegboard
by applying a steadily increasing load on the hook until either the pegboard or the hook failed.
HOOK DESIGN IS USUALLY MORE IMPORTANT THAN PEGBOARD STRENGTH
A detailed description of the hooks tested, the testing procedure and the test results appears
later in this article.
Briefly, test results indicated that many common types of pegboard hooks will perform almost
equally well installed either in a pegboard panel of medium-strength or high-strength.
3
Figure 1
Test frame with test in progress.
METHOD
DESIGNED
TO TEST
CAUSES FOR
OCCASIONAL
PROBLEMS Apparently manufacturers of these hooks design them so that they yield before they cause
tearout and thus permanently disfigure the pegboard.
It appears that
pegboard strength does not become a significant factor until the loading
becomes very heavy
, that is more than 40 lbs. at the end of a 6 hook, assuming medium to
high-strength pegboard. Hook design was found to be far more important to load-carrying
capacity than the type of pegboard used for medium-weight loading (15 to 25 lbs. at the end of
a 6 hook).
It also appears that hook design has an important bearing on the performance of the peg-
board; under the same loading, some hooks will deface the pegboard whereas others will not.
As a supplier of pegboard, we prefer a hook design which causes the hook to yield before it
scars or breaks the pegboard. Also, in consideration of safety, we prefer a hook which yields
through bending of the prong or tangs rather than by sudden breaking, which could drop a load
on a bystander.
To this point in this article, we have described hook loading as, for example, 40 lbs. at the
end of a 6 hook. Two factors determine the stress placed on the pegboard panel, the
weight
placed on the hook and the
leverage
of that weight. A 40 lb. load at the end of a 6 hook cre-
ates the same stress as 20 lbs. at the end of a 12 hook. Both loadings are described as 20 ft.-
lbs. If a 40 lb. load is distributed evenly over the length of a 12 hook, the loading would also
be 20 ft.-lbs. thenceforth we will describe hook-loading in terms of ft.-lbs.
Pegboard hooks in common use vary widely in design. Figure 2 shows one basic type.
Terminology used in Figure 2 may generally be applied to describe the four basic parts of any
hook.
Figure 3
shows and describes the 12 types of hooks tested, it may be used for easy
reference while reading the remainder of this article. In describing the hooks, the
terms,
heavy duty
and
super heavy duty
are used only if this description appears
in the manufacturers literature.
PREPARING PEGBOARD PANELS FOR TESTING
MEASUREMENTS OF PEGBOARD STRENGTH AND RIGIDITY
Pegboard panels for testing were first cut to 47 x 60. Before insertion in the test-frame we
cut a 12 x 47 piece from the 60 length of each panel and put this in a transverse-strength-
tester (Figure 4). This simple test seems to offer best correlation with the more difficult meas-
ure of hook-hanging strength.
4
TERMINOLOGY
Description
of Hooks
Tested
TANGS portion of the base inserted into the pegboard
BASE portion of the hook which supports its prong.
PRONG
hook extension for hanging merchandise
APRON bottom lip of the exposed portion of the base
(depending
on design, the apron may be a wide and rounded bearing surface which
gives good protection to the pegboard or the sharp-point of a wire-end
which easily causes damage)
Figure 2 In our testing we supported the 12 x 47
samples on a 24 span and then applied a
steadily increasing load until they broke.
Test results in Table I show the average of
three tests of each type of pegboard.

TABLE I TRANSVERSE STRENGTH TEST RESULTS
FOR PEGBOARD USED IN TRIALS
Breaking
Deflection At
Hardboard Type
Load in lbs.
Breaking Load
Medium-strength 1/4
42.3
2.9
High-strength 3/16
39.3
8.2
High-strength 1/4
57.7
6.8
Note that the high-strength 1/4 pegboard accepted a load 36% greater than the medium-
strength 1/4. Note also that the high-strength 3/16 pegboard, though accepting a breaking
load near the same as a medium-strength 1/4 pegboard deflected more than 8 inches before
breaking whereas the 1/4 deflected less than 3 inches.
The lesser defection of the 1/4 peg-
board is a decided advantage in case of marginal support of fixturing frames
where the possi-
bility of springout may exist. However, careful examination of test results later presented gives
indication that the more-rigid, medium-strength 1/4 pegboard may be more susceptible to dam-
age from heavily-loaded hooks than the more-flexible, high-strength 3/16 and 1/4 pegboard.
We started with six 47 x 60 pegboard panels of each of the three types. After cutting the
12 x 47 strip for transverse-strength-testing, the remaining 47 x 48 panels were marked in 9
places for hook testing locations. These marked locations are visible on Figure 1.
No marked location on a pegboard panel was used for more than one test, nor was a single
hook used for more than one test, even though the test caused no evidence of hook or board
weakening. Each of the 12 types of hooks was tested at least twice on each type of hardboard.
When there was substantial disagreement between two tests, additional tests were run until con-
sistent results were obtained.
HOOKS GENERALLY FAILED
BEFORE THE PEGBOARD
DESIRABLE SINCE HOOKS
ARE EASIER TO REPLACE
(See
Figure 6
for a bar chart of test results.)
Test results are shown in the bar chart,
Figure 6
, alongside the fold-out description
of hooks tested,
Figure 3
, for ease of cross-
reference.
Table II
describes more specifi-
cally how each failure occurred.
To get a mental picture of the various levels of loading used to bring about failure, refer to
Figure 5
. This shows a typical heavy-duty application with loading in the range of 15 to 20 ft.-
lbs.
5
Figure 4
Testing pegboard for stength and rigidity.
Figure 5
An example of hook-loading averaging 15 to 20 ft.- In our test results you will note that two-thirds of the hooks tested would have failed under
this loading. You will also note that the maximum loading used in our testing (34 ft.-lbs.) was
double the loading shown in
Figure 5
.
Our conclusions regarding the performance of the thr