Janka hardness test understand which woods are harder than others. Janka hardness test The Janka hardness test (from the Austrian-born emigrant Gabriel Janka, 1864-1932) measures the resistance of a sample of wood to denting and wear. It measures the force required to embed an diameter steel ball halfway into a sample of wood. A common use of Janka hardness ratings is to determine whether a species is suitable for use as flooring. The hardness of wood varies with the direction of the wood grain. Testing on the surface of a plank, perpendicular to the grain, is said to be of "side hardness". Testing
Les Janka in international affairs and the formulation of U.S. foreign and defense policy. A graduate of the University of Redlands, Janka received a master's degree in International Relations and Middle East Studies from the School of Advanced International Studies at Johns Hopkins University. Janka worked for the United States Information Agency from 1964 to 1968 and was Assistant Dean of the School of Advanced International Studies of Johns Hopkins University from 1968 to 1971, when he was appointed Special Assistant to Henry Kissinger on the National Security Council at the White House. Janka became Senior National Security Council Staff Member for