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
93 George Street, The Rocks development of The Rocks. The site has scientific significance for the archaeological potential to reveal evidence of road surfaces and earlier buildings on the site. The building is socially significant for its long history, and for its contribution to The Rocks area, Australia's premier heritage precinct. Shop, Zia Pina Pizzeria was listed on the New South Wales State Heritage Register on 10 May 2002 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The site of 91 and 93 George Street is historically significant as