About the Author
JankaHardnessScale.com is a Ready Utilities project. Here's a bit on who built it and why it exists.
Cedrick Reese, Founder of Ready Utilities
Cedrick Reese is a retired veteran and the founder of Ready Utilities. He started building for the web in the early 2000s through affiliate marketing and niche content sites. That work narrowed over time into one thing: free tools and calculators people could actually use.
After retiring from service, he went back to school three times:
- Computer Systems Technician
- UEI College
- Electro-Mechanical Technologies
- Tulsa Welding School
- Carpentry Program
- Florida State College at Jacksonville
These days he builds furniture using traditional joinery, keeps a garden, and keeps adding to the library of free tools.
Why a Wood Hardness Tool
In the shop, the question of which wood is harder comes up all the time. The Janka test answers it with a number: the force it takes to push a 0.444-inch (11.28 mm) steel ball halfway into a wood sample. Every species gets measured the same way, so the numbers are directly comparable. Going through the Carpentry program at Florida State College at Jacksonville made that comparison a routine part of planning a project, whether it was a tabletop, a workbench, or a floor. This site puts that reference online, free, for anyone else working through the same question. That's what the interactive Janka tool is here for.
Editorial Approach
The Janka values on this site come from two sources: The Wood Database (wood-database.com) and the USDA Forest Products Laboratory Wood Handbook. Both are the standard references in woodworking and flooring. The numbers follow ASTM D143 methodology, taken from clear heartwood samples at 12 percent moisture content. They're averages, not guarantees. Red oak is the common North American reference point, with published values ranging from around 1,220 to 1,290 lbf depending on the source and test method used. The figures here are for comparing species, not predicting how a finished floor will hold up.
The about page covers how the site is set up. For questions about a specific species or data point, the contact page is the right place.
A note on Janka values: According to the Wikipedia entry on the Janka hardness test, the method was developed in 1906 by Austrian-born American researcher Gabriel Janka (1864–1932), adapting the Brinell hardness test already in use for metals. Results show up in different units depending on the source: pounds-force (lbf) in the U.S., kilograms-force (kgf) in Sweden, and newtons (N) in Australia. The published number for each species is an average. There's a standard deviation behind every one of them, but most sources don't publish it alongside the figure.