Indentation hardness test, performed with either 3 gf or 9 gf loads, preceded the development of microhardness testers using traditional indenters. In 1925, Smith and Sandland of the UK developed an indentation test that employed a square-based pyramidal indenter made from diamond. They chose the pyramidal shape with an angle of 136° between opposite faces in order to obtain hardness numbers that would be as close as possible to Brinell hardness numbers for the specimen. The Vickers test has a great advantage of using one hardness scale to test all materials.The first reference to the Vickers indenter with low loads was made
145 George Street, The Rocks group as a whole, contributes to a precinct unique to NSW with its historic associations and streetscape character. The group is an important part of The Rocks Heritage Conservation Area being sympathetic in scale and character and an extension of the remaining earlier buildings of George St, presenting a unified streetscape. The buildings are tangible evidence of the redevelopment of The Rocks in the last decade of the 19th century and first decade of the 20th century. 145 George Street has high social significance as a contributory element associated with the historic character of The Rocks, which is held in