Fiberboards 



2881 



TEMPERED SIS 



DRY, SEMI -DRY 



V't\/ 



6,000 



3.000 



4,000 5,000 



TENSILE STRENGTH (PSD 



6,000 



Figure 23-105. — Tensile strength parallel to surface of y4-inch-thick commercial hard- 

 boards tested at 6 to 8 percent moisture content. (Top) Eleven tempered hardboards. 

 (Bottom) Three standard hardboards. See table 23-11 for descriptions of boards 

 tested. (Drawing from Suchsland and Woodson 1985, based on data from Werren 

 and McNatt 1975, text footnote 5.) 



The variability found by Werren and McNatt in '/4-inch hardboards is illustrat- 

 ed in the following figures (magnitude of variation in '/n-inch boards was 

 comparable): 



Property Figure 



Modulus of elasticity in bending 



Modulus of rupture 



Tensile strength parallell to surface 



Tensile strength perpendicular to surface (internal bond strength) 



23-103 

 23-104 

 23-105 

 23-106 



Average properties of the boards described in table 23-11 are tabulated as 

 follows: 



