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
Lilyvale, The Rocks is an integral component of a group of 19th century houses in this section of Cumberland Street, which evokes a traditional Rocks streetscape. "Lilyvale" (176 Cumberland Street), the Butchery Building (178-180 Cumberland Street) & Hart's Building (10-14 Essex Street) as a group: The surviving buildings occupying the block bounded by Cumberland, Essex and Gloucester Streets, south of the Cahill Expressway, collectively illustrate the range and diversity of small scale development in this area of The Rocks between 1840 and World War I. They combine with nearby precincts to the south of Essex Street to extend that diversity into the early