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 decades of the 20th century. The buildings on the site combine to form an interesting group, reminiscent of the lively and diverse early streetscapes and urban scale of The Rocks. "Lilyvale" 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. "Lilyvale" (176 Cumberland Street) is an integral component of a group of 19th century houses in this section of Cumberland Street, which collectively illustrate the range, diversity and urban scale of