On the tensile strength and hardness relation for metals

A method for predicting the ultimate tensile strength (S sub u ) of a material from Brinell-type hardness tests is described for several metals including steel, aluminum, and copper alloys. The prediction of S sub u is based on a consistent relationship between S sub u and a material's hardness coefficient, K sub d . A simple experimental procedure for determining K sub d from indentation-hardness test data is presented. The relationship between S sub u and K sub d is found to be 1/3 for all cubic metals. Comparisons between predicted and experimentally determined values of S sub u are made for each of the materials studied, and sources of error between the two S sub u values are discussed.