Grade B7 is a heat treated chromium molybdenum low alloy steel with a minimum tensile strength requirement of 125 ksi (860 Mpa), a yield strength of 105 ksi (720 Mpa) and a maximum hardness of 35HRC. Boltport produces B7 headed and headless bolts from alloy steel AISI 4140 bar stock or forgings. A193 Grade B7 is the most commonly used bolting size, plus A194 Grade 2H nuts are used for bolting carbon steel pipe. A193 B7 bolts are available in metric sizes from M6 to M180 and imperial sizes from 1/4 to 7 inches in diameter.