The phrase "grade steel" refers to different types or levels of steel that have specific qualities or characteristics. It helps categorize steel based on its strength, durability, and other properties. Full definition
This truck brings back the idea of high grade steel to boost passenger safety. (classicgaragedfw.com)
The reason is that it is made from commercially grade steel frame. (abmachinesguide.com)
It is also important to point out that this table has an incredibly high capacity thanks to its aircraft - grade steel support cables. (geekwrapped.com)