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 majority of external render was removed and the brick walls painted. As at 30 March 2011, "Lilyvale" and site are of State heritage significance for their historical and scientific cultural values. The site and building are also of State heritage significance for their contribution to The Rocks area which is of State Heritage significance in its own right. "Lilyvale" Cottage is a very fine and rare example of Colonial Regency freestanding domestic architecture in the city centre. It is in good condition, having been conserved in 1987 by SCRA, and retains much of its early form and materials. The cottage