Janka hardness test 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 the cut surface of a stump is
Walter Janka Mann's novel of dynastic decline, Buddenbrooks, which was to be a collaboration between East Germany's DEFA and West German film companies. Another ambition, in pursuit of which he met Charlie Chaplin near the latter's home at Vevey in May 1954, was a DEFA film with Charlie Chaplin as the leading star. On 6 December 1956 Walter Janka was arrested on a charge of Counter-revolutionary conspiracy and held in the Berlin-Hohenschönhausen Remand Prison. By March 1957 he had become one of six men arrested and held in respect of the alleged conspiracy. Janka remained in the Berlin-Hohenschönhausen prison for more than