Manufactures & Suppliers of Pipes, Tubes, Flanges, Pipe Fitting & Fasteners

Grade L7 fasteners are essential components in demanding applications, particularly in the petrochemical, oil, and gas industries. These fasteners are manufactured according to the ASTM A193 specification, which outlines the requirements for high-strength bolting materials suitable for high-temperature and high-pressure environments. ASTM A193 Grade L7 fasteners are specifically engineered for use in critical applications where strength and durability are paramount. These fasteners are primarily utilized in the petrochemical and oil and gas industries, where they play a vital role in maintaining the integrity of pressure vessels, piping systems, flanges, and valves under extreme conditions.

ASTM A193 Gr. L7 Stud Bolt, ASTM A193 Gr. L7 Bolt, ASTM A193 Gr. L7 Nuts, ASTM A193 Gr. L7 Fasteners Supplier and Manufacturer in Mumbai, India

One of the key advantages of ASTM A193 Grade L7 fasteners is their enhanced resistance to corrosion and stress corrosion cracking. This makes them an ideal choice for use in challenging environments, including those exposed to harsh chemicals or high humidity. The fasteners undergo stringent heat treatment processes to improve their performance characteristics, ensuring they can reliably perform in critical applications.


Grade L7 fasteners are available in various sizes and configurations, including both standard and custom thread pitches. While they are often found in national coarse (UNC) thread pitches, applications requiring diameters above one inch typically use an 8 threads per inch (tpi) specification to ensure optimal assembly strength.

ASTM A193 Gr. L7 Fasteners Chemical Composition

ElementSymbolPercentage (%)
CarbonC0.35% max
ManganeseMn0.60% - 0.90%
PhosphorusP0.04% max
SulfurS0.05% max
SiliconSi0.15% - 0.40%
ChromiumCr1.00% - 1.25%
MolybdenumMo0.15% - 0.25%

ASTM A193 Gr. L7 Fasteners Mechanical Properties

PropertyValue
Yield Strength70 ksi (minimum)
Tensile Strength100 ksi (minimum)
Elongation20% (in 8 inches)
Reduction of Area50% (minimum)
Hardness197 HB (maximum)
Impact Strength30 ft-lbs at -20°F