Rockwell scale Rockwell scale The Rockwell scale is a hardness scale based on indentation hardness of a material. The Rockwell test determines the hardness by measuring the depth of penetration of an indenter under a large load compared to the penetration made by a preload. There are different scales, denoted by a single letter, that use different loads or indenters. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale (see below). When testing metals, indentation hardness correlates linearly with tensile strength. This important relation permits economically important nondestructive testing of
101 George Street, The Rocks history of New South Wales. The place possesses a degree of rarity as the first site to be the subject of heritage renovations/reconstructions in the 1970s, when the plans of the Sydney Cove Redevelopment Authority to raze The Rocks for redevelopment were still in place. The place is important in demonstrating the principal characteristics of a class of cultural or natural places/environments in New South Wales. The scale and streetscape character of the Phillip's Foote building is representative of early 19th commercial building in The Rocks as a plain two-storey shop with residence. 101 George Street, The Rocks 101 George