ASTM A193 Grade B7 Heavy Hex Bolts

ASTM A193 Grade B7 Heavy Hex Bolts are high-strength alloy steel fasteners specified under ASTM A193/A193M for bolting used in high-temperature and high-pressure service.

Grade B7 is a chromium-molybdenum alloy steel grade that is heat treated to achieve the mechanical properties required by the specification.

Headed bolts supplied to ASTM A193 are typically manufactured in a heavy hex pattern, with dimensional requirements referenced to ASME B18.2.1.

These bolts are commonly used for bolted flange connections, valves, fittings, pressure vessels, and piping systems where elevated temperature, pressure, and mechanical loading require alloy steel bolting.

They are particularly common in petrochemical, oil and gas, power generation, chemical processing, and industrial equipment applications.

For inch-series products, thread forms are generally specified according to ASME B1.1, while heavy hex head dimensions follow ASME B18.2.1. Typical commercial configurations include UNC threads for smaller diameters and 8UN threads for larger diameters, subject to the applicable specification and purchase requirements.

ASTM A193 Grade B7 Heavy Hex Bolts are commonly paired with ASTM A194 Grade 2H heavy hex nuts in pressure-equipment and piping applications.