- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 28 Jul 2021
Janka hardness rating scale
The Janka hardness rating scale was named after Gabriel Janka (1864–1932), an Austrian wood researcher. His work was based on similar studies conducted by August Brinell (1849 –1925), a Swedish metallurgical engineer.
Janka and Brinell were interested in the surface hardness of materials. In both instances, the men conducted tests based on the amount of pressure or effort required to press a steel ball into a certain substance to a specific depth.
The Janka hardness test measures the force required to embed an 11.28 millimetres (0.444 in) diameter steel ball halfway into a sample of wood. This measurement is recorded and repeated several times until an average can be calculated. The end result is the Janka hardness rating.
The Janka scale has become an industry standard for comparing wood flooring. The scale is also useful in the construction industry for giving builders a sense of how difficult it will be to work with different types of wood.
 Related articles on Designing Buildings Wiki
Featured articles and news
ECA skills recharge at the House of Commons
Electrical sector feels skills shortage bite.
CIOB Academy’s course take-up inked to external factors.
Q and A with self-representing artist, Hannah Shergold.
And publishes three-year strategic plan.
Introducing changes to make it more effective from 2024.
Shortlist announced for 2023 public choice award vote.
The last of the Victorians. Book review.
An exotic name that is shrouded in mystery.
Fropm practice to research and the business of materials.
Terms, histories, theories and practices.
Alteration and everything else before demolition.
And CIOB's response.
Presidential update from CIAT's Eddie Weir PCIAT.
Rates freeze, NI cuts, full expensing; early election?
Could this be a remedy for condensation, damp or mould?
Unlocking a Healthier Tomorrow
Call for ministerial group and National Retrofit Delivery Plan.