http://en.wikipedia.org/wiki/Hydrochloric_acidThe link above will tell you about hydrochloric acid.
I was thinking common "pool supply" muriatic acid was quite a bit less than 100%, thinking around 40%. Turns out that about 40% is about all that can be produced.
The strength needed seems to be about 18% for steel pickling. 36% would surely be effective at stripping the oxide scale.
From wikipedia
Pickling of steel
One of the most important applications of hydrochloric acid is in the pickling of steel, to remove rust or iron oxide scale from iron or steel before subsequent processing, such as extrusion, rolling, galvanizing, and other techniques.[6][8] Technical quality HCl at typically 18% concentration is the most commonly used pickling agent for the pickling of carbon steel grades.
