2622 



Chapter 22 



Table 22-14 — Percentage distortion of diagonal lengths of 48- by 40-inch pallets of 22 

 hardwood species after 6 and 12 feet fall drops onto one corner from a height of 40 inches 



(Stern 1978)i-2 



Distortion of diagonal length after 

 Species 6th drop 12th drop 



—Percent 



Ash, green 1.3 1 .6 



Yellow-poplar 1.3 1.7 



Hackberry 1 .4 1.7 



Sweetgum 1.5 1.8 



Maple, red 1.5 1.9 



Elm, American 1.5 1.9 



Sweetbay 1.6 2.0 



Oak, water 1.6 2.0 



Ash, white 1.6 2.0 



Oak, scarlet 1.7 2.1 



Elm, winged 1.7 2.1 



Oak, cherrybark 1.7 2.1 



Oak, Shumard 1.7 2.1 



Oak, northern red 1.7 2.1 



Tupelo, black 1.8 2.2 



Oak, blackjack 1.8 2.3 



Oak, black 1.8 2.3 



Oak, post 1.9 2.5 



Oak, southern red 2.2 2.8 



Oak, white 2.3 2.9 



Hickory, mockemut 2.5 3.1 



Oak, laurel 2.7 4.0 



Average 1.8 2.2 



'See figure 22-31 for design of pallets; each value is an average based on five pallets. 

 ^Pallets had approximately 12 percent moisture content at test. 



STAPLED PALLETS OF PINE-SITE HARDWOODS 



Stem (In press a) staple-assembled pallets having the same dimensions as the 

 nail-assembled pallets depicted in figure 22-31, using wood of 17 pine-site 

 hardwoods available from his 1978 experiment, and performed simultaneously 

 with it. The stapled pallets were assembled green using tool-driven 2-'/2-inch- 

 long, 15-gauge, 7/16-inch-crown, plastic-coated staples — 144 per pallet. 



Static bending stiffness of the stapled pallets was about the same as that of 

 nailed pallets. Impact rigidity of the stapled pallets, however, was only about 

 one-fifth that of the nailed pallets. Readers needing more details should consult 

 Stem (In press a). 



