Skip to Main Content
Janka hardness using nonstandard specimensAuthor(s): David W. Green; Marshall Begel; William Nelson
Source: Research Note FPL-RN-0303. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 13 p.
Publication Series: Research Note (RN)
Station: Forest Products Laboratory
Download Publication (954 KB)
DescriptionJanka hardness determined on 1.5- by 3.5-in. specimens (2×4s) was found to be equivalent to that determined using the 2- by 2-in. specimen specified in ASTM D 143. Data are presented on the relationship between Janka hardness and the strength of clear wood. Analysis of historical data determined using standard specimens indicated no difference between side hardness values determined on the radial face as opposed to the tangential. Analysis of historical data also indicated that the relationship between hardness modulus (HM) and Janka hardness (H) may be different for hardwood species than for softwood. Recommendations are given for ensuring that experimental procedures do not bias the results when testing non-standard specimens. The authors caution that if hardness(ASTM D 143) and hardness modulus (ASTM D 1037) are measured simultaneously for each ball penetration, the HM/H ratio may be different than that given in D 1037 because the two standards specify different rates of penetration.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationGreen, David W.; Begel, Marshall; Nelson, William. 2006. Janka hardness using nonstandard specimens. Research Note FPL-RN-0303. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 13 p.
KeywordsJanka hardness, hardness modulus, Douglas-fir, 2×4
- Properties and grading of Danto and Ramon 2 by 4’s
- Experimental shear strength of unchecked solid-sawn Douglas-fir
- Hardness evaluation of cured urea-formaldehyde resins with different formaldehyde/urea mole ratios using nanoindentation method
XML: View XML