low-carbon steel, containing no more than 0.25 percent carbon.
Origin of mild steel
First recorded in 1865–70
Also called soft steel.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for mild steel
any of a class of strong tough steels that contain a low quantity of carbon (0.1–0.25 per cent)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012