a numerical expression of the hardness of a metal as determined by a test (Rockwell test) made by indenting a test piece with a Brale, or with a steel ball of specific diameter, under two successive loads and measuring the resulting permanent indentation.
We Are Number One
Read more in this article about some frequently asked questions and fun facts related to our definitions.
Why Veterans Day And The Number 11 Are Tied Together
November 11th is the 315th day of the year (except on leap years). It’s also Veterans Day, a federal holiday honoring all military veterans.
Origin of Rockwell number
1930–35, Americanism; named after Stanley P. Rockwell, 20th-century American metallurgist
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019