Janka Hardness Ratings for Various Species of Wood (pounds)

Hardness is defined as resistance to indentation using a modified Janka hardness test, measured by the load required to embed a 11.28-mm (0.444-in.) ball to one-half its diameter. Values presented are the average of radial and tangential penetrations.(1)

(1) The Wood Handbook - Wood as an engineering material, USDA, General Technical Report 113.