cold rolled steel is made to tighter/closer tolerances, and square edged, and machines better, it can also be easier to forge weld,
Usual proceedure for machining was to take a skim off each side to relieve the surface tension induced by the cold rolling process, then finish machine. it used to have a lead content to make it free cutting
The hot rolled stuff comes in made to much wider tolerances, and shapes are not always square edged or square, or even straight, or consistent. But that doesn't matter if you are going to forge it to shape.
One advantage over here in the UK is that when restoring old ironwork, you can get the cold rolled in imperial or metric table. Useful when trying to match sized bars or replace individual bits.
I use the cold rolled for making tools that have to be fitted together eg sliding bits like on rams/slideways or smith's helpers.
The hot rolled stuff comes in made to much wider tolerances, and shapes are not always square edged or square, or even straight, or consistent. But that doesn't matter if you are going to forge it to shape.
hot rolled vs cold rolled
in Blacksmithing, General Discussion
Posted
The hot rolled stuff comes in made to much wider tolerances, and shapes are not always square edged or square, or even straight, or consistent. But that doesn't matter if you are going to forge it to shape.
I find this interesting.