Olea capensis wood materials. It is also the one of the world's hardest woods according to the Janka hardness test. The timber has a good abrasion resistance and is very strong. It is an excellent turnery wood, and is used for a wide range of decorative items. Olea capensis Olea capensis, also known by the common name black ironwood, is an African tree species belonging to the Olive family (Oleaceae). It is widespread in Sub-Saharan Africa from the east in Somalia, Ethiopia and Sudan, south to the tip of South Africa, and west to Cameroon, Sierra Leone and the Islands of the
Scratch hardness Wooddell, working at the Carborundum Company, extended the scale further by using resistance to abrasion, and extrapolating the scale based on seven for quartz and nine for corundum, resulting in a value of 42.4 for South American brown diamond bort. Resistance to abrasion is less affected by surface variations than other methods of indentations. There is a linear relationship between cohesive energy density (lattice energy per volume) and Wooddell wear resistance, occurring between corundum (H=9) and diamond (H=42.5). Scratch hardness Scratch hardness tests are used to determine the hardness of a material to scratches and abrasion. The earliest test was