Table of Contents

ASTM A193 Grade B7, ASTM A193 Grade B7 Bolt, Nuts, ASTM A193 Bolt Manufacturer in India – Ananka Group

ASTM A193 Grade B7 provides the specification for the bolts, studs, threaded rods, and other overhead bolting fasteners made of high-strength, alloy steel. It gives the requirements for high-pressure and high-temperature conditions in petrochemical, oil and gas industries, power generation, and other industrial uses requiring reliable performance under extreme conditions.

ASTM A193 Grade B7: Chemical Composition and Properties

ASTM A193 Grade B7 bolts are composed of chromium-molybdenum steel. These bolts possess outstanding mechanical properties with high tensile strength, abrasion resistance, and resistance to many other heat retaining jobs. The typical quenching and tempering of the fasteners within this grade is performed for the improvement of performance properties and can be used under high temperature conditions up to 450°C (840°F).

Advantages of ASTM A193 Grade B7 Bolts:

High Tensile Strength: The chrome-moly alloy composition, and the quenching, along with tempering, inherent in these bolts provide good tensile and yield strength that makes these perfect for applications of high stress.

Heat Resistance: Grade B7 bolts can tolerate up to 450° C or 840° F without any degradation in its mechanical properties, thus ideal for application in boilers, pressure vessels, and piping systems subjected to elevated temperature.

Corrosion Resistance: The presence of chromium provides moderate corrosion resistance for slight oxidation or minor chemical exposure.

Flexibility: ASTM A193 Grade B7 bolts may be used with A194 Grade 2H nuts, and this opened up many of the uses of flanges, valves, and fittings.

In industrial applications requiring not only significant strength but also resistance to heat, B7 bolts are just so tough. ASTM A193 Grade B7 bolts ensure not only the performance in critical application environments but also safety.

There are many grades covered, including ferritic steels and austenitic stainless steels with designations such as B5, B6, B7, B8, B8M, and so on.

ASTM A193 Grade B7 Chemical Composition

Element	Alloy Steel
	Chromium Molybdenum Steel^A
	composition, %
Carbon	0.37 – 0.49^C
Manganese	0.65 – 1.10
Phosphorus	0.035 max
Sulfur	0.040 max
Silicon	0.15 – 0.35
Chromium	0.75 – 1.20
Molybdenum	0.15 – 0.25

ASTM A193 Grade B7 Mechanical Composition

Diameter, inch.	Tensile Strength, min, ksi	Yield Strength, min, 0.2% offset, KSI	Elongation in 4D, min, %	Reduction of Area, min, %	Hardness, max
					Hardness, max	2-1⁄2 and under	125	105	16	50	321 HBW or 35 HRC
					over 2-1⁄2 to 4, inclusive	115	95	16	50	321 HBW or 35 HRC
over 4 to 7, inclusive	100	75	18	50	321 HBW or 35 HRC