ANSI A135.4-2012 Basic Hardboard (Newer version available)
ANSI A135.4 defines hardboard, covers requirements and test methods for water absorption, thickness swelling, modulus of rupture, tensile strength, surface finish, dimensions, squareness, moisture content, and edge straightness of five classes of basic hardboard. Where appropriate, test methods in ASTM D 1037 are required. Methods of identifying hardboard that conforms to ANSI A135.4 are provided.
Key topics covered by the ANSI A135.4 Basic Harboard:
dimensional, physical and mechanical requirements
classification by thickness and physical properties
NOTE: This standard was revised in 2020.