It is recognised that grinding media wear can represent up to 50% of the operating costs of a given tumbling mill. Over the years, a number of works have explored the development of different ways and means to both understand grinding media wear as Well as model and predict it. The focus of the present work is to examine the differences in microstructure, hardness, abrasion and impact toughness of grinding media from eight different manufacturing sources. Results will be presented for 125 mm diameter media typically used for SAG mills. A discussion will address any issues highlighted by the results than may contribute to predictive wear model development as well as indicate possible directions for future research. (C) 2016 Elsevier Ltd. All rights reserved.