Instead of being produced from all high-grade steel, most of The Guardian is produced in mostly forms of carbon fiber and thick polycarbonate as well as some steel.

FORBES: Connect

Every ton of high-grade yields six hundred kilos of steel.

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Coking coal is high grade coal used in the production of steel.

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For example, Soviet pipeline builders have routinely cut corners by using lower-grade steel and shallow burial of lines, making pipes particularly vulnerable to corrosion and repeated, catastrophic accidents.

CENTERFORSECURITYPOLICY: Center For Security Policy

The focus of the proxy battle and the source of Birmingham's financial woe is the division that makes high-grade bar steel for critical applications like seatbelt bolts and motor shafts.

FORBES: Iron Wills