SPACING of Or SIXPENNY and EIGI1TPENNY I MULTI-NAIL

RICULTURE ROOM

SPACING orOF SIXPENNY AND EIGI1TPENNY I

WIRE NAILS IN DOUGLAS-FIR

MULTI-NAIL JOINTS

August 1960

No. 2155

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UNITED STATES DEPARTMENT OF AGRICULTURE FOREST PRODUCTS LABORATORY FOREST SERVICE MADISON 5, WISCONSIN En Cooperation with the University of Wisconsin SPACING OF SIXPENNY AND EIGHTPENNY WIRE NAILS IN

DOUGLAS-FIR MULTI-NAIL JOINTS1

AGUSTIN N. RAMOS, Jr. Research Associate from the Philippines 2 Forest Products Laboratory, — Forest Service U. S. Department of Agriculture

Introduction

Nails are probably the simplest and most, common fastenings for wood construction. In a framed structure, nails must resist direct withdrawal, lateral displacement, or both kinds of forces. Direct withdrawal is the force that pulls the nail out lengthwise, while lateral displacement causes the nail to bend or shear under load applied at right angles to its length (1).1 Other things being equal, nails resist greater lateral than direct withdrawal loads. For this reason, it is recommended that, whenever possible, nails should be used only in sus taining lateral loads (LI) 2).

In the design of a nailed joint, the Wood Handbook and the National Design Specification for Stress-Grade Lumber and Its Fastenings provide little information on joints made up of more than one common wire nail. While these publications provide for the individual lateral nail-holding properties of different species of wood for the different sizes of common wire nails, no information on the allowable end distance, edge distance, and spacing of nails, both parallel and perpendicular to the grain of wood, is given.

Lateral nail-holding properties given in the Wood Handbook and in the National Design Specification for Stress-Grade Lumber and Its Fastenings were derived from results of laboratory tests in which the splitting

1This report is based on a thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Civil Engineering) at the University of Wisconsin. -Maintained at Madison, Wis., in cooperation with the University of Wisconsin. Underlined numbers in parentheses refer to Literature Cited.

Report No. 2155 tendencies of the wood were not taken into account. There arises the question as to how a number of nails in a particular joint should be spaced to provide maximum joint strength and how the strength of a multiple-nail joint compares with that of a single-nail joint.

The lateral load-carrying capacity of a nailed joint depends upon the resistance of the nailed wood to compression parallel and perpendicular to the grain, the shearing and flexural strength of the nails, the size and depth of penetration of the nails, the friction between the members of the joint, the splitting tendency of the wood, and the specific gravity and moisture content of the wood (6, 2). In general, the splitting of the nailed joint probably contributes the greatest loss in lateral holding power of nails in use. For any particular wood, the extent to which it will split depends upon the thickness of the member, the size, point, and spacing of the nails, and consequently on the wedging effect of the nails (a) when driven into the wood and (b) under the action of the lateral load.

In view of the variables that affect the lateral holding power of nails, this study was confined to determining the minimum spacings of sixpenny and eightpenny common wire nails under lateral loading. The work was done on air-dried Douglas-fir. Joints were tested in tension and compression soon after nails were driven. The joints were designed in such a way that nails were stressed in single shear. The placement of the nails in the joint was varied to study the following nail spacings (fig. 1):

(a) Spacing parallel to the grain of wood. (b) Spacing perpendicular to the grain of wood. (c) Unstressed end distance. (d) Stressed end distance. (e) Edge distance.

Materials

The materials used in this study were selected on the basis of their general usage in construction and their availability at the Forest Products Laboratory. The construction grade of Coast-type Douglas-fir (Pseudotsuga menziesii) was chosen. The 4- by 4-inch lumber, having an actual cross section of 3-1/2 by 3-1/2 inches, had been surfaced on all four sides and air dried. Material of this size permitted nailing a cleat on each of two opposite sides of the block without risking collision of the nail points in the block. Cleats for the eightpenny nails were 3/4 inch thick and those for sixpenny nails 5/8 inch thick. These thicknesses permitted a penetration of at least 2/3 of the nail shank into the block (4). The bright sixpenny and eightpenny common wire nails used had diamond points and plain shanks free from any form of coating or surface film that tends to increase the lateral nail-holding power. The average shank diameters of these nails were 0.113 and 0.131 inch, respectively, and their corresponding lengths were about 2 and 2-1/2 inches.

Report No. 2155 -2- Processing of Specimens

A total of 33 pieces of Douglas-fir lumber, each nominally 4 by 4 inches in cross section and 16 feet long, were carefully inspected to exclude any with serious defects, such as knots, decay, and cross-grain, which_ impair strength properties. To determine the suitability of the pieces for experimental use, a random check for moisture content was conducted with an electric moisture meter. The lumber was found to have an average of 14 percent moisture content.

Each piece selected was smooth and flat on all four sides, so that no further dressing was deemed necessary. Each piece was then marked for cutting to final specimen lengths. Figure 2 shows typical cutting dia- grams for each piece to obtain end-matched specimens. During, the marking process, necessary measures were undertaken to cull the defective portions of each piece. An allowance of 1/8 inch was made in marking the piece to final specimen length to allow for the width of the saw kerf. The portions designated for cleats were sawn along the grain into four equal parts and surfaced to the desired uniform thickness. For the tension specimens, a hole 21/32 inch in diameter was drilled 4-1/2 inches from the outer end of each block and each cleat at the center of their width. A 5/8-inch bolt was put in each hole to apply tension load to the joint.

When all blocks and cleats had been cut, they were conditioned to equi-. . librium with 75° +1° F. and 64 +1 percent relative humidity. This tem- perature and humidity brought them to an average moisture content of about 12 percent. The conditioning period lasted for about 2 weeks before the lateral nail-resistance tests were conducted.

Preparation and Testing of Specimens

A total of 183 nailed joint specimens were evaluated for lateral nail resistance. Of these, 111 were loaded in compression and 72 in tension.

All material was used for a pair of specimens--that is, first for a single-nail and then for multiple-nail joint specimen. This procedure had a two-fold purpose: It served as a "control" in comparing the strength of the multiple-nail joints to that of the corresponding single- nail joint; and it minimized to a certain extent the effect of variations in specific gravity within the tree on the lateral hail holding strength of the specimens.

To make the single-nail joint, the specimen was fastened together with one nail driven into each side at the center of the lapped area of the joint. Multiple-nail specimens were fastened together with four or more nails on each side, depending upon the nailing pattern used for the joint.

Report No. 2155 -3-

During a preliminary investigation on one compression specimen, 0.02-inch metal spacers were used to provide uniform space between the members of the joint. The spacers were very difficult to remove from the multiple- nail joint, however, and were therefore omitted from all specimens.

Figure 3 shows a typical multiple-nail joint for the compression test. The nailing pattern indicates the size and number of nails required for the specimen, and the location at which each nail was driven.

Tables 1 and 2 summarize the various nailing patterns used. Hence, Series Nos. 10 and 100 represent a group of specimens made with sixpenny and eightpenny common wire nails, respectively, to determine the minimum spacing of nails parallel to the grain of the wood under lateral loading.. This arrangement permitted determining each of the five nail spacings independently from one another by varying one nail spacing for each series while the other spacings were unchanged.

To get a fair average value for the lateral nail-holding strength per nailing pattern, the test was repeated three times. To measure the slip at the joint, a dial gage was fastened to one edge of each cleat, as shown in figure 3. A small wood bracket was nailed to one face of the block so that the movable shaft of the dial gage bore on the bracket in an initial position that kept the slip of the joint during the test within the range of dial reading.

The specimen was placed vertically on the testing machine. The load was applied parallel to the grain of the block and cleat, and throughout the test at four successive testing machine head speeds, as follows:

Head speed, Slip range, Inch per minute Inch

0.007 0 - 0.020 .014 0.021 - .050 .080 .051 - .300 .160 .301 - to failure

During the test, the load at different increments of slip was taken until maximum load was reached. Head speed was increased at the slips tabu- lated above-to accelerate the test.

Immediately after the test on the single-nail joint, the nails were with- drawn from the wood, and the nailing pattern for a particular multiple- nail specimen was marked on each cleat. The procedure of preparing and testing the multiple-nail joint (fig. 3) was similar to that for a single- nail joint. Upon completion of the multiple-nail test, a moisture sample about an inch in length, free from knots and other defects, was cut from the block. The specific gravity of the block was determined, based on its volume at the time of test and its ovendry weight.

Report No. 2155 -4- For the tension specimen, the nailed joint was originally designed to be composed of a pair of cleats and a pair of blocks. A preliminary investigation, however, showed that the resulting data for the average deformation of the joint were unsatisfactory due to the unevenslippage of the two cleats from the block. A modified tension specimen (fig was then made to consist of a single cleat fastened to the block with an overlapping length of about 9 inches. The method of preparing and testing the modified tension specimen was similar to that of compression. specimens.

In view of the non-symmetry of the modified tension specimen with respect to the line of action of the lateral load, a slight eccentricity was introduced. The eccentricity was roughly equal to one-half the thickness of the cleat. As a consequence, one would expect that the resulting lateral nail-resistance strength for the tension specimens would be slightly lower than that of the compression specimens, since the resulting moment due to the eccentricity would tend to pull the nails from, the block in the direction of its length. Observations made to this effect, however, proved otherwise. The effect of eccentricity on the lateral nail-holding power of the tension specimens is further discussed later in this report.

Results of Investigation

Tables 3 to 7 summarize the results of the lateral nail-resistance tests for the various series of nail spacings in which nails are stressed in single shear. These values are the average results of three replications, and may, therefore, vary considerably from the lateral nail- holding strength of any one replication. For a particular nailing pattern in Series 200 tests, for instance, the individual maximum lateral nail-holding properties of three replications range from 316 to 500 pounds, whereas the average for these specimens is 427 pounds.

The results of this study apply only to air-dried Douglas-fir materials having an average moisture content of about 12 percent. The tests were conducted on the specimens soon after the nails were driven. Pertinent adjustments should be applied to the results if used under conditions different from that of this study. The Wood Handbook (29 gives such adjustments for use of nailed joints.

Report No. 2155 Evaluation of Results

This study is concerned mainly with the determination of the minimum nail spacing under lateral loading in which the nails are loaded in single shear. No attempt was made to correlate the results given herein with the allowable nail-holding strength as recommended by the Forest Products Laboratory (2) or by the National Design Specification for Stress-Grade Lumber and Its Fastenings (4).

The true limit of proportionality for this lateral nail-resistance study cannot be well defined from the load-slip curves. For purposes of setting allowable lateral loads for common wire nails, Scholten (5) arbitrarily seta limit at a joint slip of 0.015 inch. The slip at maximum load is much greater than 0.015 inch, but the latter value represents a practical limit that can be tolerated in use. Such deformation at an early stage of loading nailed joints points out the importance of taking into consideration the deformation in designing nailed frame structures.

The specific gravity of the Douglas-fir used in this study ranged from 0.41 to 0.50, based on volume at the time of test and on ovendry weight (tables 3 to 7, col. 4). The average specific gravity, 0.46, is slightly lower than the average specific gravity of 0.48 for Douglas-fir (Coast-type), based on volume at 12 percent moisture content and ovendry weight (2). Since previous investigations by the Forest Products Laboratory (9) indicate that the lateral nail-holding strength of wood varies directly with its specific gravity at some exponential value, the results shown in tables 3 to 7, columns 5 and 8, were adjusted to the average Douglas-fir specific gravity of 0.48 for purposes of comparison. Adjustments were made for the lateral nail-holding strength of the specimens at a joint slip of 0.015 inch and at maximum load by using a simple ratio:

0.48 1.75 (1) P - ) Pt Sp. G.

where P is the adjusted lateral nail-holding strength of the specimens at 0.413 specific gravity, based on volume at the time of test and on ovendry weight; „Pt the lateral nail-holding strength of the specimens as tested; Sp. G. tfig specific gravity of the specimens, based on volume at time of test and ovendry weight; and 0.48 is the average specific gravity for Douglas-fir, based on its volume at 12 percent moisture content and ovendry weight.

The exponential value of 1.75 for the spetific gravity used in the adjust- ment was derived from two componeats. Scholten (5) used an exponent of 1.50 in comparing the lateral nail-holding'strength of different species, Since the strength values for pieces of wood within species vary by a higher power of the specific gravity values than do average strength

Report No. 2155 -6- values of different species, the Forest Products Laboratory (9) recom- mends that the exponential value of 1.50 for the specific gravity be increased to 1.75 to include the strength variation within species. The adjusted values for the lateral nail-holding strength are given in columns 6 and 9 of tables 3 to 7. Table 8 summarizes the average lateral load per nail for each series for comparing results of single-nail joints tested in compression and tension.

The adjusted lateral nail-holding values for the multiple-nail joints with different nail spacings and the values for the corresponding single- nail joints or "controls" are expressed as a ratio in columns 7 and 10 of tables 3 to 7. It was noted that a number of these values exceeded 100 percent, which meant that these particular multiple-nail joint specimens have greater lateral nail-holding properties than the corresponding single-nail control. Theoretically, such load ratio values should not exceed 100 percent, except for the variability of the wood, the effect of friction, and the experimental errors that may have been inadvertently introduced during the testing of the specimens.

A plot relating load ratio values in percent, on the ordinate scale, to the nail spacings in inches, on the abscissa showed that the irregularly dispersed coordinate points seemed to assume a hyperbolic curve. Hence, a general hyperbolic equation was derived in the form:

(y•100) xa = -K (2) y 100 - ;ET where x is the load ratio value, expressed in percent; x the nail spacing, in inches; and a and K are constants whose value depends upon the disper- sion of the coordinate points.

Equation (2) was derived on the assumption that the load ratio value's cannot exceed 100 percent, and the hyperbolic curve was therefore made asymptotic to the straight line:

y - 100•0 (3)

Similarly, the hyperbolic curve was made asymptotic to the Y-axis, since the minimum load ratio value is zero.

In figures 5 to 14 are given the graphical representations of the relations between the load ratio values and the nail spacings. Two different hyperbolic-curve segments were plotted on the same coordinate axes for each series of tests to represent the relations at a joint slip of 0.015 inch and at maximum load. Figures 5 to 14 also show graphically the

Report No. 2155 -7- relation of nail spacing to the observed average "relative splitting" of the specimens (a) following the nailing operation and (b) at the maximum load, expressed in percentage of the length of a "total split of a specimen," as given in tables 3 to 7, columns 12 and 13. By "total split of a specimen" is meant the splitting of the nailed joint along the full length of the cleats for the compression specimens, or along the full length of the lapped portion of the cleat for the tension specimens.

At this point, it should be noted that the values of the "relative splitting" of the specimens depend on the skill of the researcher in driving the nails into the individual specimen and on his personal preference in evaluating the resulting failures. Observations made when nails were driven into the individual specimen showed there is a greater tendency of the wood to split when nails are driven into the flat-grain face than into the edge-grain face. In specimens that are bastard cut or whose annual rings make an angle of about 45° with the sides of the wood, there was a general tendency for the nails to deflect along the softer springwood ring. The deflection tended to become more apparent when the nails were spaced closer to one another or closer to the edges or ends of the specimen.

The most Common failure in the lateral nail-resistance tests, where the spacings of the nails were not critical, was a combination in which the nail head pulled into the cleat while the nail shank pulled away from the block. Where nails were closely spaced or positioned close to the edges or ends of the specimen, failure was by splitting of the cleat along the rows of nails. Occasionally, failure was caused by the breaking of a nail at its shank. Figure 15 shows the typical failures of some nailed joint specimens. In the preparation of the individual nailed joint specimen, care was taken to assure close alinement of the nails. In joints with closely spaced hails and where splitting occurred, a steel nail guide, 1 by 1 by 2 inches in size and with a slot cut halfway along its length, was used to aline the nails perpendicularly to the face of the specimen. A slight misalinement of the nails in the joint could tend to change the center of gravity of the nails as a group, and consequently, the expected uniform load distribution on the individual nails could be altered considerably.

As was expected in the single-nail joint tests, the lateral nail-holding properties of sixpenny nails are less than those of the eightpenny nails (table 8). Columns 4 and 5 show that the average lateral nail loads at a joint slip of 0.015 inch and at maximum load for sixpenny nails are about 78 and 69 percent as great, respectively, as those of eightpenny nails. Table 8 also shows that the expected lessening of lateral nail- holding power due to eccentricity in tension specimens is not significant. Columns 4 and 5 show that, for a particular size of nail, the average lateral nail-holding power in the tension tests is even greater than that in compression tests.

Report No. 2155 -8- In general, the curves relating load ratio to nail spacing (figs. 5 to 14) exhibit the same trend; that is, the load ratio values tend to decrease as the spacings of the nails are reduced. A majority of the curves followed the general trend of hyperbolic curve. However, Series 20, in which the nails were variably spaced perpendicular to the grain, showed that the splitting of the wood did not tend to decrease the lateral holding power of the nails, since all computed load ratio values for this particular series of tests at the maximum load exceeded 100 percent.

While the results of tests for Series 20 contradicted those of Series 200 (table 4, col. 10, and figs. 7 and 8), it appeared that, at maximum load, the wedging effect of the smaller diameter nail to split wood is less than that of the larger nail. No numerical relation, however, between the splitting of wood and the diameter of nails can be established. Compari- son of the extent of splitting of a specimen for a given nail spacing of sixpenny nails, expressed in percent, shows that the values of the "relative splitting" are less than those of the eightpenny nails . (tables 3 to 7, cols. 12 and 13, and figs. 5 to 14). Similarly, sixpenny nails give a higher value of load ratio than eightpenny nails.

To determine a reasonable spacing of the individual nails which will provide optimum load-carrying capacity per nail without excessive splitting before and after the nailing process, a preferred nail spacing for each series of tests was obtained, taking into consideration the combined effect of the following factors:

(1) The magnitude of the load ratio value of the specimens.

(2) The extent of splitting of the specimens, termed the "relative splitting."

(3) The difficulty encountered in driving the nails into the specimens.

The values of the preferred range of nail spacing for each series of tests are determined graphically from figures 5 to 14 and are summarized in table 9. Values in columns 4 and 5 of this table are obtained from the graphs in figures 5 to 14 which show the range of nail spacing bounded by two heavy, vertical straight lines. Column 6 shows the average values of load ratio, in percent, that correspond to the preferred range of nail spacings, as obtained from figures 5 to 14. As the nails were spaced closer together than the preferred range of nail. spacings, the corresponding values of the load ratio of the specimens decreased rather sharply, while the "relative splitting" values increased in the same proportion. Similarly, when nails were spaced further apart than the preferred range of nail spacings, the load ratio values increased very slightly almost attaining the 100 percent mark. Correspondingly, the extent of splitting of the individual specimen is lessened.

Of the different series of tests, column 6 of table 9 shows that the lateral nail-holding properties of nailed jointsare most affected by

Report No. 2155 -9- splitting of the wood near the edges. The average load ratio values for Series 40 and 400 are 87 and 92 percent, respectively, indicating a mean reduction in the lateral nail-holding power of about 10 percent. It is expected that such reduction will further increase as the grain of the nailed wood members deviates from the longitudinal axis of the nailed joint. Similarly, the lateral nail-holding power is least affected by splitting when nails are driven closer together perpendicular to the grain of the wood. Results of tests on Series 20 and 200 specimens gave load ratio. values of. 99 and 95 percent, respectively, indicating a mean reduction of only 3 percent in the lateral holding power of the nails. Such a small reduction is to be expected, since wood splits only along the grain.

For purposes of simplicity, the preferred range of bail spacing for each series of tests (table 9, col. 5) was reduced to a single average value in terms of the nail diameter to represent the recommended minimum lateral nail spacing (table 10, col. 2). Since the average load ratio values Of Series 40 and 400'are relatively low compared with those of other series of tests, the recommended minimum nail spacing from the edges of the wood was increased from 8 times the shank diameter to 10 times. Figure 16 shows the recommended minimum spacings for nails subjected to lateral loading in single shear.

Comparison of Results with Previous Nail Studies

In a comparative study on nail spacings, no attempt was made to correlate directly the findings in this study with the results of previous research. The conditions under which the laboratory tests were conducted in previous work On nails are not fully known. It is possible that the laboratory test conditions in each of these nail studies differ from one another.

According to a particular specification, Stern (7) reported that at least four tails should be used if given design values are to be applied to a nailed joint. While the lateral carrying capacity of common wire nails increases directly with the number of nails, Stoy and Fonrobert (8) recom- mend that the allowable loads be decreased by 10 and 20 percent if more than 10 and 15 nails, respectively, are arranged in a row in a particular nailed joint. No information, however, was given as to the placement and spacings of the tails in the joint.

In this lateral nail-resistance study, the number of nails used for the different specimens ranged from four to eight. The number of nails per row ranged from two to three, depending upon the nailing pattern of the joint, as shown in tables 1 and 2. For this number of nails, the mean load ratio value of all the series of tests shown in table 9, column 6, was found to be about 94 percent, or an average 6 percent reduction in the load-carrying capacity of a single-nail joint subjected to lateral loading in single shear.

Report No. 2155 -10- Nails should be so spaced as to avoid unusual splitting of the wood (4, 2). Recommendations of Stay and Fonrobert (8) and two other foreign government specifications on the spacing of nails, as reported by Stern (I), are summarized in table 10. For purposes of comparison, the recommended minimum lateral nail spacings in this study are given in column 2. For a given nail spacing, it is noted that the recommendations of the German Government Specification on the spacings of nails when staggered by one nail diameter (col. 3) are roughly about one-half those recommended in column 2. This seems reasonable, since the lateral nail- holding property of the nailed joint is slightly affected by splitting due to nails being spaced closely together perpendicular to the grain of the wood.

Recommendations of the Russian Government Specification are given in column 4 of table 10. Recommendations of the British Government Speci- fications for nail spacings in joints without prebored nail holes and in joints with prebored nail holes are shown in columns 5 and 6, respectively. As expected, the nail spacings for joints with prebored holes are less than those for joints without prebored hales, since preboring tends to lessen the splitting of the wood. Marten (3) stated that, for nailed joints with prebored nail holes, the lateral load-carrying capacity, in the direction of the wood fibers, of common wire nails driven into the side grain of the wood members is 1.8 times greater than if nails are driven without preboring into slow-grown wood, and 1.5 times greater if driven into fast-grown wood, since greater load-carrying capacity is offered by the bearing area of end fibers cut during boring than by the areas along those fibers which are wedged apart during nail. driving. On the other hand, if the lateral load is applied perpendicularly to the wood fibers, the effect of preboring is reversed, but such a decrease in lateral load-carrying capacity is smaller than the above increase. No study on the effect of preboring nail holes,however, was attempted in this investigation.

In general, the recommendations on the minimum nail spacings given in columns 3, 4,` 5, and 6 are more conservative than those recommended in column 2 of table 10. It should be remembered, however, that the lateral load-carrying capacity of the individual nails used in multiple-nail joints for this study is 6 percent less than that of the single-nail joint. Such a reduction holds true only for nails laterally loaded in single shear. Furthermore, these recommendations apply only to air-dried Douglas-fir materials and to the laboratory conditions stated previously. To determine the applicability of these recommendations to other species of wood of different specific gravity, and to correlate the corresponding reduction in the lateral nail-holding power to the number of nails for a given nail spacing in a particular nailed joint, are beyond the scope of this lateral nail-resistance study.

Report No. 2155 -11- Conclusions

(1) For the recommended minimum nail spacings given in table 10, column 2, the lateral holding power of the individual common wire nails is reduced by about 6 percent.

(2) The lateral holding power of nails is reduced about 10 percent by the splitting of the wood which results from driving the nails about 8 times the diameter of the nail from the edges of the members. It is reduced about 3 percent by the splitting of the wood when the nails are spaced about 7 times the diameter of the nail perpendicular to the grain of the meMbers.

(3) The tendency of wood to split under the wedging action of sixpenny nails is less than under that of eightpenny nails.

(4) The occurrence of the limit of proportionality at a very small deformation of the nailed joint points out the need of caution in designing nailed frame structures.

(5) In the single-nail joint tests, the lateral nail-holding properties of sixpenny nails at a joint slip of 0.015 inch and at maximum load are about 78 and 69 percent, respectively, of those of eightpenny nails.

Report No. 2155 -12- Literature Cited

(1) Markwardt L. J., and Gahagan, J. M. 1936. Proper Nailing of Car Bracing. Forest Products Laboratory Report No. R1088.

and Wilson, T.R.C. 1935. Strength and Related Properties of Woods Grown in the United States. U.S. Dept. of Agric. Tech. Bull. No. 479, Washington D. C.

(3) Marten, G. 1936. Load Transmission of Nailed Joints. Forschungsberichte Holz, No. 6, Berlin, Germany.

(4) National Lumber Manufacturers Association. 1957. National Design Specification for Stress-Grade Lumber and Its Fastenings. 1957 Edition.

Scholten, J. A. 1950. Nail-Holding Properties of Southern Hardwoods. Southern Lumberman, Vol. 181, No. 2273, pp. 208-210.

Slimes, F. E., Johanson, P. E., and Niskanen, E. 1954. On the Effect of the Properties and Quality of Wood on the Strength of Nailed Joints. Valtion Teknillinen Tutkimuslaitos, Tiedoitus 129 (English Summary), Helsinki.

(7) Stern, E. G., and Stoneburner, P. W. 1952. Design of Nailed Structures. Virginia Polytechnic Institute Bulletin, Eng'g. Expt. Sta. Series No. 81, Vol. XLV, No. 6.

(8) Stoy, W., and Fonrobert, F. 1933. Nailed Timber Construction. Translated by A. L. , Gunn. Arbeitsgemeinschaft Holz, Series No. 6, 2nd Edition.

(9) U.S. Forest Products Laboratory. 1955. Wood Handbook, U.S. Dept. of Agric, Agriculture Handbook No. 72, Washington, D. C.

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Table 3.--Summary of lateral nail-resistance data on nail spacings parallel to grain of wood in which nails are stressed in single shear

Specimen:Type of : Nail :Specific: Average load :Load ratio:Average maximum : Load ratio:Average: Relative 1 • nailed per nail at : at slip : load per nail : at maximum: joint : splitting No .- • :BPacings:gravityE: joint :slip 0.015 inch :0.015 inch: load based:slip at: based on :Actual:Adjusted2: on single-:maximum: During: At nailing:failure • :Actual:Adjustedl ; single- : nail : load : • nail : strength : • • • • : strength :

• . . (1) (2) :• (3) (4) (5) (6) • (7) : ( 8 ) • (9) : (10) : (11) : (12) : (13) • • . In. : Lb. Lb. : Percent : Lb. : Lb. : Percent : In. :Percent:Percent

: 0.804 : O 0 6-11 :Multiple: 3 : 0.47 : 139 : 144 384 : 398 96 : Single : : 146 : 151 95 : 401 : 416 .938 :

388 .875: : 5 6-12 :Multiple: 2-1/2 : .47 : 141 : 146 : 374 96 : Single : : 136 : 141 104 : 388 : 403 .887:

:Multiple: 2 .47 : 144 : 149 : 408 .779 : O : 5 6-13 104 : 393 102 Single : : 138 : 143 : 386 : 400 .784 :

148 : 380 : .693: O : 15 6-14 :Multiple: 1-3/4 : .47 : 143 : 394 99 •• Single : : 144 : 149 99 : 383 : 397 .781:

6-15 :Multiple: 1-1/2 : .48 : 126 : 126 340 : 340 86 .571 : 5 : 30 Single : : 163 : 163 77 : 395 : 395 : .801

6-16 :Multiple: 1-1/4 : .47 : 120 : 124 : 320 : 332 .527 : 10 : 40 85 74 Single : : 141 : 146 : 431 : 447 .784 :

.48 : 123 : 123 : 331 : 331 .548 15 50 6-17 :Multiple: 76 86 : Single : : 162 : 162 : 385 : 385 •779

8-101 :Multiple: 3 .47 : 172 : 178 : 499 : 518 94 .758 o 5 : Single : : 177 : 184 97 : 530 : 550 : 1.099 8-102 :Multiple: 2-1/2 : .47 : 158 : 164 : 478 : 496 .811 5 : Single : : 182 : 189 87 : 500 : 519 96 .972 8-103 :Multiple: 2 .47 : 157 : 163 : 496 : 515 : .675 5 15 Single : : 172 : 178 91 : 536 : 556 : 93 1.119

.728 • 10 : 15 8-104 :Multiple: 1-3/4 : .48 : 173 : 173 84 : 558 : 558 : 88 • Single : • 205 : 205 : 632 : 632 : .845

1-1/2 : .49 : 167 : 161 462 .527 15 4o 8-105 :Multiple: : 479 : 70 : Single : : 218 : 210 77 : 685 661 : .982

:8-106 :Multiple: 1-1/4 : .49 : 144 :20 : 380 : 367 : .466 6o 139 78 69 Single : : 185 : 178 : 554 : 535 : 1.020

8-107 :Multiple: 1 .47 : 135 : 140 :344 357 .386 : 30 : 80 Single : : 181 : 188 75 : 544 : 564 63 : 1.181 :

1Number before dash indicates nail penny size, number after dash the series and specimen. Specific gravity based on volume at time of test and weight when ovendry. 1Lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48. Report No. 2155

Table 4.--Summary of lateral nail-resistance data on nail spacings perpendicular to grain of wood in which nails are stressed in single shear

Specimen:Type of : Nail :Specific: Average load :Load ratio:Average maximum :Load ratio:Average: Relative No.1 : nailed :sPaciags:gravityE.: per nail at : at slip : load per nail :at maximum: joint : splitting, : joint : :slip 0.015 inch :0.015 inch: , :load based:slip at. ,. based on :Actual:Adjusted2:on single-maximum: During: At :Actual:Adjusted2: single- : nail : load :nailing:failure : : nail : : strength : • : strength :

(1) : (2) : (3) : (4) : (5) : (6) : (7) : (8) : (9) (10) : (11) : (12) : (13)

: In. Lb. : Lb. : Percent ; Lb. Lb. ; Percent : In. :Percent:Percent

6-21 :Multiple: 1 0.47 ; 129 : 134 : 0.740 : 0 0 100 : 327 : 339 : 107 Single : : 129 : 134 : 306 : 317 : : .731 :

6-22 :Multiple: 3/4 : .46 : 143 : 154 : 347 374 : .931 : 0 : 103 : : 103 Single : : 139 : 150 : 337 : 363 : : 1.069 :

6-23 :Multiple: 1/2 .46 : 138 : 149 .863 : 0 : 0 : 327 : 352 102 Single : : 139 : 150 99 : 322 : 347 .636 : 6-24 :Multiple: 3/8 : .46 : 153 : 165 : : 402 : .871 0 30 89 : 373 101 • Single : : 172 : 185 370 : 399 .982 :

6-25 :Multiple: 1/4 .46 : 133 : 354 381 0 : 143 105 : .829 : : 25 Single : : 143 : 154 93 : 338 : 364 : .960 8-201 :Multiple: 1 .45 : 150 : 168 : 367 : 411 : .129 : 2 Single : : 151 : 169 99 : 390 : 437 94 .8o8

8-202 :Multiple: 3/4 : .46 : 149 : 161 339 : 365 84 : .622 : 7 : 20 Single : : 157 : 169 95 ,F021. : 433 : 1.1.085 : 8-203 :Multiple: 5/ 45 : 150 : 168 495 : 1.038 : 5 ! 15 104 : Single : : 167 : 187 90 : 423 : 474 : .965 8-204 :Multiple: 1/2 .46 : 146 : 157 : 427 : 46o : : .794 : 10 : 30 • Single : : 189 : 204 77 : 473 : 510 .899 : 8-205 :Multiple: : .46 : 145 : 156 : 38o : 409 3/ 8 85 : .594 15 40 Single : : 185 : 199 78 : 445 : 479 : 1.173 : 8-206 :Multiple: 5/16 : .46 : 136 : 146 : 388 418 .770 : 91 20 : 35 Single : : 147 : 158 93 : 428 : 461 : : 1.157 :

1Number before dash indicates nail penny size, number after dash the series and specimen. Specific gravity based on volume at time of test and weight when ovendry. Lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48.

Report No. 2155

Table 5.--Summary of lateral nail-resistance data on nail spacings from the unstressed end of the wood in which nails are stressed in single shear

Specimen:Type of : Nail :Specific: Average load :Load ratio:Average maximum :LoaS ratio:Average: Relative No.1 : nailed :spacings: gravity=: per nail at : at slip : load per nail :at maximum: joint : splitting : joint : :slip 0.015 inch :0.015 inch. :load based:slip at: . • based on :Actual:Adjuste dl:on single-:maximum: During: At .• :Actual:Adjusted3-: single- : . nail : load :nailing:failure • . : nail : • strength : ..• • : strength • • • • • • (1) (2) (3) : (4) : (5) : (6) : (7) : ( 8 ) (9) (10) (11) (12) ; (13)

In. Lb. : Lb. • Percent • Lb. Lb. :• Percent In. :Percent:Percent

6-31 :Multiple: 1-1/2 : 0.46 135 : 145 0.811 : 0 : 0 • 102 • 350 : 377 105 Single : 132 : 142 • 332 : 358 .917 :

• 6-32 :Multiple: 1-1/4 : .46 : 143 : 154 : 368 : 396 .870: 0 • 5 96 108 • : Single : 149 : 160 341 : 367 .852: •

1386-33 :Multiple: 1 .46: 149 : 361 : 3 : 10 100 389 98 .759: 138Single : : 149 : 367 : 395 .908 •

1336-34 :Multiple: 3/4 : .46: 143 : 349 : 376 .734 10 • 30 142: Single : : 153 : 362 : 390 96 .874 :

1/2 1356-35 :Multiple: : .47: : 140 : 362 : 375 .807 : 20 : 50 138: Single : : 143 98 : 384 : .398 .943

6-36 :Multiple: 1/4 : .47 : 121 125 : 360 : 373 90 .828 : 35 : 60 : Single : : 135 140 : 371 : 385 97 .929 :

1.1158-301 :Multiple: 1-3/4 .45 : 166 186 : 2 96 : 497 : 557 92 5 : Single : 172 193 : 543 : 608 •943 :

.458-302 :Multiple: : 1-1/2179 : 200 : 507 : 568 .882 : 10 : 25 103 100 : Single : : 174 195 509 : 570 : 1.045 :

8-303 :MUltiple: 1-1/4 .45 : 159 : .178 509 : 570 .828 : 10 : 25 : Single : : 161 180 99 : 564 : 632 90 : 1.122 :

.5768-304 :Multiple: 1 .48 : 157 157 : 414 : 414 : 20 : 50 : Single : 174 174 : 565 : 565 73 1.160 :

.7058-305 :Multiple: 3/4 .46 : 164 177 : 497 20 : 45 : 461 : 82 : Single : 166 179 99 : 560 : 603 : 1.147 :

8-306 :Multiple: 1/2 .46 : 132 142 50 : 80 82 : 353 : 380 70 •575 : Single : : 161 173 : 502 : 541 .786 :

-Number before dash indicates nail penny size, number after dash the series and specimen. 2 -Specific-gravity based on volume at time of test and weight when ovendry. -Lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48.

Report No. 2155

Table 6.--Summary of lateral nail-resistance data on nail spacings from the edges of the wood in which nails are stressed in single shear

Specimen:Type of : Nail :Specific: Average load :Load ratio:Average maximum :Load ratio:Average Relative splitting No.1 : nailed :spacings: avity–2: per nail at : at slip : load per nail :at maximum: joint : joint : gr :slip 0.015 inch :0.015 inch. •load based:slip at .• . 3 . based on :Actual:Adjusted2:on single-:maximum: During: At :Actual:Adjusted–: single- : : nail : load :nailing:failure nail : : strength : • • : strength :

(1) : (2) : (3) : (4) (5) (6) • (7) • (8) ; (9) : (10) : (11) : (12) : (13) • . . • In. : Lb. : Lb. ; Percent ; Lb. ; Lb. ; Percent ; In. :Percent:Percent

6-41 :Multiple: 1 : 0.49 : 130 : 125 : 346 : 334 0.859 : o : 5 82 94 : Single : : 158 : 152 369 : 356 : .916 :

6-42 :Multiple: 3/4 : 130 : 121 .691 : 0 2 : 346 : 322 88 Single : : 145 : 135 90 : 392 : 365 .995 : 6-43 :Multiple: 1/2 : 117 : 109 : 298 : 277 : .742 : 5 : 15 : Single : : 137 : 128 85 : 372 : 346 80 .879 :

6-44 :Multiple: 3/8 .42 : 113 : 143 : 331 : 418 .863 : 3 10 : Single : 130 : 164 87 : 367 : 463 90 .947 :

.436:6- 45 :Multiple; 1/4 : .43 : 106 : 129 : 255 20: 309 : : 65 : Single : : 138 : 167 77 : 395 : 479 1.099 :

6-46 :Multiple: 3/16 : .42 : 85 : 107 183 : 231 : .376 : 6o 52 : 35 : Single : : 128 : 162 : 355 : 448 .956 : .8768-401 :Multiple: 1 .46 : 137 : 148 : 406 :: 437 0 Single : : 143 154 96 : 437 : 471 93 .751 : 8-402 :Multiple: 3/4: .47 : 175 : 182 406 421 .687 : 5 : 15 92 Single : • : 190 : 197 : 531 : 551 : 76 : 1.229 : .8318-403 :Multiple: 5/8 .48 : 158 : 158 : 426 : 426 : 0 10 92 101 : Single : : 172 : 172 : 422 : 422 .816 :

8-404 :Multiple: 1/2 .45 : 154 : 172 : 463 : 4 : 15 : 40 519 86 .93 : Single : : 195 ; 218 79 : 541 606 .900 :

8-405 :Multiple: 3/8 : .46 : 126 : 136 : 343 : 370 .518 : 20 2 45 Single : : 161 : 173 78 : 549 : 591 : .922 :

8-406 :Multiple: 1/4 .45 : (4) : (4) (4) : (4) loo ( 4 ) (4) (4) : loo Single : : 175 : 196 54'3 : 658 : .974 :

–Number1 before dash indicates nail penny size, number after dash the series and specimen. -Specific gravity based on volume at time of test and weight when ovendry. -Lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48. -Tests on multiple-nail joints were not conducted due to serious splitting of the specimens when nailed.

Report No. 2155

Table 7.--Summary of lateral nail-resistance data on nail spacings from the stressed end of the wood in which nails are stressed in single shear

Specimen:Type of : Nail :Specific: Average load :Load ratio:Average maximum :Load ratio:Average: Relative No.1 : nailed :gPaciags:grvity?: per nail at : at slip : load per nail :at maximum: joint : splitting joint :slip 0.015 inch :0.015 inch: ,:load based:slip at: . . , based on :Actual:Adjusted2 :on single-:maximum: During: At • . . :Actual;Adjusted2; single-: . : nail : load :nailing:failure . . . nail : : strength : : . . .• : •. : • strength : ...... (1) : (2) • (3) ; (4) ; (5) • (6) (7} ; ( 8 ) (9) : ( 10 ) : (11) : (12) : (13) .: . . . In. ; Lb. ; Lb. ; Percent ; Lb. Lb. : Percent : In. :Percent:Percent

6-51 :Multiple: 2-1/2 : 0.47 149 0.908 0 ! 0 104 103 : Single : : 138 : 143 : ; 3g(33. ; 1-:. : .959 :

6-52 :Multiple: 2 .47 : 125 : 13 : 369 : 383 : .788 : 0 0 8 9 Single : : 140 : 145 • 388 : 403 : 95 .832 :

6-5 :Multiple: 1-3/4 ! .47 : 150 : 156 : : 374 : 388 .716 : : 5 92 102 Single : : 163 : 169 : : 365 : 379 : .844 :

6-54 :Multiple: 1-1/2 ! .43 : 118 : 143 • 343 : 416 : .856 : 25 101 : Single • : 127 : 154 93 : 340 : 412 1.067 : :

6-55 :Multiple: 1 .43 : 120 • 146 : 356 : :844. : 0 : 20 432 : 94 Single : : 125 : 152 : 96 1.044 :

6-56 :Multiple: 3/4 .43 : 117 : 142 87 : 30747 435679 86 5 : 35 : Single : : : 135 : 164 : : 355 : 43o : .979 :

8-501 :Multiple: 3 .41 : 172 0 0 : 226 : : 494 96 1.042 : Single : : 186 : 245 93 : 512 : 674 : : 1.212 :

8-502 :Multiple: 2-1/2 ! .41 : 166 : 219 : : 485 • 638 : 1.037 : 0 0 : Single : : 173 : 228 : 969 : 45o : 593 180 •945 :

8-503 :Multiple: 2 .41 : 163 : 215 : 486 : 640 : : 1.103 : 0 : 0 : Single : : 174 : 229 : 94 : 513 : 676 : 95 : 1.162 :

8-504 :Multiple: 1-3/4 ! .44 : 18o : 209 : 489 : 569 .594 : 10 : 30 85 82 : Singlee , : 211 : 246 : 599 : 697 : .897 :

8-505 :Multiple: 1-1/2 ! .43 • 168 : 204 : 516 : 626 .618 : 10 : 89 35 : Single : : 170 : 206 : 99 : 582 : 706 . .832 :

8-506 :Multiple: 1 .43 : 165 : 200 : : 464 : 563 .565 : 20 : 60 : Single : : 196 : 238 : 84 : 591 : 716 79 .898 :

Number before dash indicates nail penny size, number after dash the series and specimen. 2 –Specific gravity based on volume at time of test and weight when ovendry. -Lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48.

Report No. 2155

Table 8.--.Comparison of results on single-nail joints laterally loaded in compression and tension in which nails'are stressed in single shear

Series : Direction : Size of : Average lateral : Average maximum. No. : of : nails : load per nail : lateral loadl- loading : at slip 0.015 : inchl (1) : (2) (3) : (4) (5)

Penny : Lb. Lb. 407 10 : Compression : 6 : 151 20 : Compression : 6 : 155 358 30 : Compression : 6 : 148 383

Average. • 151 383

4o : Tension 6 151 409 50 : Tension 6 154 413

Average 152 411

Average, compression and tension 152 394

100 : Compression : 8 : 190 574 200 : Compression : 8 : 181 466 300 : Compression : 8 182 587

Average 184 543

400 : Tension 8 185 542 500 : Tension 8 : 232 : 677

Average • 208 610

Average, compression and tension 194 569

!Average lateral load per nail adjusted to the average Douglas-fir specific gravity of 0.48.

Report No. 2155

Table 9.--Summary of preferred nail spacings for laterally loaded joints in which nails are stressed in single shear

: • Nail spacings :Series :Size : Preferred :Equivalent: Average : No. : of : range of : nail :load-ratio :nails: nail spacing:spacing in: terms of : : . nail : . : : : diameter

(1) : ( 2 ) : (3) : (4) : (5) • ( 6 )

: :Penny: In. Percent

Parallel to grain • 10 : 6 : 1.75 - 2.00 : 16 - 18 •• 97 : 100 : 8 : 2.00 - 2.50 : 15 - 19 90

Perpendicular to grain •. 20 : 6 : 0.50 - 0.75 : 4 - 7 •. 99 • 200 • 8 : 0.75 - 1.00 : 6 - 8 : 95

Unstressed end distance : 30 : 6 : 1.00 - 1.25 : 9 - 11 98 : 300 : 8 : 1.25 - 1.50 : 10 - 12 : 93

Edge distance : 40 : 6 : 0.75 - 1.00 : 7 - 9 :. 87 400 : 8 : 0.75 - 1.00 : 6 - 8 : 92

Stressed end distance : 50 : 6 : 1.50 - 1.75 : 13 - 16 : 94 500 8 : 2.00 - 2.50 : 15 - 19 : 94

Report ,No. 2155

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Report No. 2155 P

0 0 0

P P

Figure 1. --Typical joints fastened with nails in single shear subject to lateral load in different directions. A - Three-member nailed joint subject to compression load in Series 10, 20, 30, 100, 200, and 300. B - Two-member nailed joint subject to tension load in Series 40, 50, 400, and 500.

The letter a denotes spacing of nails parallel to the grain of the wood; b, spacing perpendicular to grain; c, unstressed end distance; d, stressed end distance; and e, edge distance.

Report No. 2155 N

0 04 Figure 3. --Typical multiple-nail joint specimen loaded in compression; nails are stressed in single shear.

ZM 115 565

Report No. 2155 Figure 4. --Modified single-nail joint and multiple-nail joint specimens loaded in tension; nails are stressed in single shear.

ZM 115 568

Report No. 2155 NAIL SPACING IN INCHES 0 2 3

P P /2 /2

LEGEND: '0-0' LOAD RAT/0 NAIL SPACING CURVE AT SLIP 0.0/5 INCH -0- -0- LOAD RATIO NAIL SPACING CURVE AT MAX. LOAD RELATIVE SPLITTING DURING NAILING 80 120 t t RELATIVE SPLITTING AT MAX. LOAD PREFERRED RANGE OF NAIL SPACING

Z /00

= /00 29'20 o 80 y X3.55 / 1:1 'ct

42.60 y= 100 0 60 X3.85

5D /OD /50 20D 250 300 1 1 1 I 1 J i / 2 3 NA/L SPACING IN INCHES AND /N TERMS OF NA/L DIAMETER Z M 118 062

Figure 5. --Relationship of spacing of sixpenny nails parallel to grain (S,eries 10) to load ratio and relative splitting of nailed joint showing the preferred range of nail spacing. Report No. 2155 LEGEND: 0 0 LOAD RATIO NAIL SPACING CURVE AT SLIP 0.0/5 INCH /201 -0- -0- LOAD RATIO NAIL SPACING CURVE AT MAX. LOAD MEM RELATIVE SPLITTING DURING NAILING I RELATIVE SPLITTING AT MAX. LOAD

2 3 NAIL SPACING /N INCHES AND IN TERMS OF NA/L DIAMETER Z M 118 063

Figure 6. --Relationship of spacing of eightpenny nails parallel to grain (Series 100) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing.

Report No. 2155 NAIL SPACING /N INCHES

0 0

20 141

P/2

LEGEND: 40 -0-0- LOAD RATIO NA/L SPACING CURVE AT SLIP 0.015 /NCH NAIL SPACING CURVE AT MAX. LOAD -0- -CY LOAD RATIO 4. tr) IMO RELATIVE SPLITTING DURING NAILING SPLITTING AT MAX. LOAD 4.1 1 1 RELATIVE 60 i I

PREFERRED RANGE OF NA/L SPACING /20 H 80

/00 0 CC 0 y. 100 * 4.412'33

I 80 0./0 y.. /00 X3.88 1.2

O 't 60

20 40 60 80 /OD 1 _I 1_____ 00 _I_

z x 118 064 NAIL SPACING IN INCHES AND IN TERMS OF NAIL DIAMETER

Figure 7. --Relationship of spacing of sixpenny nails perpendicular to grain (Series 20) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing.

Report No. 2155 0

LEGEND : '0-0- LOAD RATIO NA/L SPACING CURVE AT SL IP 0.015 /NCH -o- -o- LOAD RATIO NAIL SPACING CURVE AT MAX. LOAD - 60 - n111 RELAT/VE SPLITTING DURING NA /L ING `7( RELATIVE SPLITTING AT MAX LOAD

/20 80

PREFERRED RANGE psi OF NAIL SPACING K /00 Lu 0

0 q y 00 4.86 80 X0.9/

3.55 y = 100 x O 0 60

2D 40 6D 8D

Z M 118 065 NA/L SPACING IN INCHES AND /N TERMS OF NAIL DIAMETER

Figure 8. --Relationship of spacing of eightpenny nails perpendicular to grain (Series 200) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing. Report No. 2155 LEGEND : -0-0- LOAD RAT/0 NAIL SPACING CURVE AT SLIP 0.015 INCH -0- -0- LOAD RATIO NA/L SPACING CURVE AT MAX. LOAD RELATIVE SPLITTING DURING NA/LING — 80 RELATIVE SPLITTING AT MAX. LOAD

2.19 0 O

PREFERRED RANGE OF NA/L SPACING

3D 6D 9D /2D 150 0 0 /% 2

Z M 118 066 NAIL SPACING /N INCHES AND /N TERMS OF NAIL DIAMETER

Figure 9. --Relationship of spacing of sixpenny nails from unstressed end of wood (Series 30) to load ratio and relative splitting of nailed joints, showing preferred range of nail spacing.

Report No. 2155 NAIL SPACING IN INCHES 1

LEGEND• '0—'0- LOAD RATIO NA/L SPACING CURVE AT SLIP 0.0/5 /NCH -0- -0- LOAD RATIO NA/L SPACING CURVE AT MAX. LOAD /20 OMNI RELATIVE SPLITTING DURING NAILING RELATIVE SPLITTING AT MAX. LOAD

K /00

W1.44 0 0

80 oo.

n Q-4 60 y -7/00-. 11x2.06-6-2-C2 PREFERRED RANGE OF NAIL SPACING 20 40 6D 80 1/00 I /20 11 t 1 1 1 012 /-2 Z M 118 067 NA/L SPACING /N INCHES AND /N TERMS OF NAIL DIAMETER Figure 10. --Relationship of spacing of eightpenny nails from unstressed end of wood (Series 300) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing. Report Ivo. 2155 NA/L SPACING /N INCHES 0

60 LEGEND: -0--0- LOAD RATIO NAIL SPACING CURVE AT SLIP 0.0/5 /NCH -0- LOAD RATIO NAIL SPACING CURVE AT MAX. LOAD RELATIVE SPLITTING DURING NA/LING /20 RELATIVE SPLITTING AT MAX. LOAD 80

PREFERRED RANGE OF /00 NAIL SPACING

QC 1+4 0

80 O

O 0 60 /00 9.85 xa88

20 40 60 80 /OD _1_ 1 0 2 z M 118 068 NA/L SPACING IN INCHES AND IN TERMS OF NAIL DIAMETER Figure 11. --Relationship of spacing of sixpenny nails from edges of wood (Series 40) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing. Report No. 2155 NAIL SPACING /N INCHES 0 I 2

20 Qc Lu

114. (f) LEGEND: -0-0- LOAD RAT/0 NA/L SPACING CURVE AT SLIP 0.0/5 INCH 60 -0-0- LOAD RAT/0 NAIL SPACING CURVE AT MAX. LOAD OMNI RELATIVE SPLITTING DURING NAILING Lu RELATIVE SPLITTING AT MAX. LOAD

/20 80 PREFERRED RANGE OF NAIL SPACING /00 —0 -- 6.85 .0° X z /00 X/.62 80 0

4.23 y /00 X 497 60

2 40 6D 80 0 I t I 0 I 2 Z M 118 069 NAIL SPACING IN INCHES AND /N TERMS OF NAIL DIAMETER Figure 12. --Relationship of spacing of eightpenny nails from edge of wood (Series 400) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing. Report No. 2155 NA/L SPACING IN INCHES 2

111 20

LEGEND: (f) o o LOAD RATIO NAIL SPACING CURVE AT SLIP 0.0/5 INCH 60 -0- -0- LOAD RAT/0 NA/L SPACING CURVE AT MAX. LOAD RELATIVE SPLIT TING DURING NAILING kU I RELATIVE SPLITTING AT MAX. LOAD Ct

/20 PREFERRED RANGE 80 OF NA/L SPACING

K /00

0 y= /00 735 X2.00 y= /00 8. 47 80 X0.72 ct

0 60

50 /OD /50 20D 250 300 0 o 2 3 z x 118 070 NAIL SPACING /N INCHES AND IN TERMS OF NA/L DIAMETER Figure 13. --Relationship of spacing of sixpenny nails from stressed end of wood (Series 50) to load ratio and relative splitting of nailed joint, showing the preferred range of nail spacing. Report No. 2155 NAIL SPACING IN INCHES

0 2 3 O

LEGEND: -0-0- LOAD RAT/0 NA/L ,7PACING CURVE AT SLIP 0.0/5 /NCH -0- -0- LOAD RATIO NA/L SPACING CURVE AT MAX. LOAD =III=1 RELATIVE SPLITTING DURING NA IL /NG 0 C-1 RELATIVE SPLITTING AT MAX. LOAD

/20 PREFERRED RANGE ► OF NAIL SPACING 14 0

2 /00 ▪ r — _ _ .• O n -- • q0 y= /00 1522 / x I. " 80 • / / 'r( /W... 00 y=/00 48.00 / x3.03 • 6 I -4 60 I 1

50 100 1,5D 200 25D O I I I 1 I 1 0 2 3 Z M 118 071 NA/L SPACING /N INCHES AND /N TERMS OF NAIL DIAMETER Figure 14. —Relationship of spacing of eightpenny nails from stressed end of wood (Series 500) to load ratio and relative splitting of nailed joints, showing the preferred range of nail spacing. Report No. 2155 Figure 15. --Typical failures showing splitting of the cleats and nail withdrawal of nailed-joint specimens. Photo was taken after a 1-inch moisture sample had been cut from each specimen.

ZM 115 567

Report No. 2155 P P

cnI

/20 /70 /70 /20

-1---- c4

P I I 54 I

/50 /70 /70 /50

Figure 16. --Typical joints subject to lateral loads in different directions showing the recommended minimum lateral nail spacings. A - Typical two-member nailed joint subject to compression load. B - Typical two-member nailed joint subj ect to tension load.

Report No. 2155 12,17‘.-77.M-• .11RMINITRWITJOIRSIPIrnrrniesereaFE,

SUBJECT LISTS OF PUBLICATIONS ISSUED BY TI-I

FOREST PRODUCTS LABORATORY

The following are obtainable free on request from the Director, Forest Products laboratory, Madison 5 0 Wisconsin:

List of publications on List of publications on Box and Crate Construction Fire Protection and Packaging Data List of publications on List of publications on Logging, Milling, and Chemistry of Wood and Utilization of Timber. Derived Products Products

List of publications on List of publications on Fungus Defects in Forest Pulp and Paper Products and Decay in Trees List of publications on List of publications on Seasoning of Wood Glue, Glued Products and Veneer List of publications on Structural Sandwich, Plastic List of publications on Laminates, and Wood-Base Growth, Structure, and Aircraft Components Identification of Wood List of publications on List of publications on Wood Finishing Mechanical Properties and Structural Uses of Wood List of publications on and Wood Products Wood Preservation

Partial list of publications Partial list of publications for Architects, Builders, for Furniture Manufacturers, Engineers, and Retail Woodworkers and Teachers of Lumbermen Woodshop Practice

Note: Since Forest Products Laboratory publications are so varied in subject no single list is issued. Instead a list is made up for each Laboratory division. Twice a year, December 31 and June 30, a list is made up showing new reports for the previous six months. This is the only item sent regularly to the Laboratory's mailing list. Anyone who has asked for and received the proper subject lists and who has had his name placed on the mailing list can keep up to date on Forest Products Laboratory publications. Each subject list carries descriptions of all other subject lists.