Marzouk Steel, headquartered in Tunis, Tunisia, is a trusted manufacturer and supplier of high-quality steel products, serving industries that demand strength, precision, and durability. Among its specialized offerings are Alloy Steel GR B7 Fasteners, engineered for high-pressure, high-temperature, and critical mechanical applications. Manufactured using advanced technology and stringent quality control, GR B7 fasteners provide exceptional tensile strength, toughness, and corrosion resistance. Marzouk Steel ensures that every GR B7 fastener meets international standards, offering engineers and fabricators reliable fastening solutions for oil and gas, petrochemical, power generation, and heavy industrial machinery.
Alloy Steel GR B7 Fasteners are made from high-grade chromium-molybdenum (Cr-Mo) alloy steel, designed for superior tensile strength, hardness, and thermal resistance. Their chemical composition, including carbon, chromium, and molybdenum, enhances toughness, fatigue resistance, and corrosion resistance. GR B7 fasteners respond effectively to heat treatment, optimizing mechanical properties such as yield strength, tensile strength, and impact resistance. With excellent structural integrity under high-pressure and high-temperature conditions, GR B7 fasteners are ideal for critical industrial applications requiring long-term reliability, safety, and consistent performance.
Specification :Â ASTM A193 / ASME SA193
Dimension :Â DIN, ISO, ASTM, JIS, BS, GB, IS and all International Standards
Size Range :Â M3 – M56 | 3/6″ to 2″ | Custom Sizes
Length :Â 3 mm to 200 mm
| Alloy Steel B7 | C | Mn | Si | P | S | Mo | Cr |
| 0.08-0.15 | 1.00 max | 1.00 max | 0.040 | 0.030 | 0.15-0.25 | 11.50-13.50 |
| Grade | Diameter | Tensile Strength | Yield Strength | Elongation | Reduction | Hardness |
| Grade B7 | M64 and under | 860 | 720 | 16 | 50 | 321 HBW or 35 HRC |
| Over M64 to M100 | 795 | 655 | 16 | 50 | 321 HBW or 35 HRC | |
| Over M100 to M180 | 690 | 515 | 18 | 50 | 321 HBW or 35 HRC |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
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Hexagon Bolts / Set Screws |
Stud Bolts |
Hexagon Nuts |
Socket Capscrews |
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DIN 931 |
BS4882 |
DIN 934 |
DIN 912 |
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DIN 933 |
DIN 976 |
BS 1768 |
DIN 6912 |
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BS 1768 |
BS 1769 |
DIN 7984 |
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UNI 5731 |
BS 1083 |
ANSI B18.3 |
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UNI 5739 |
BS 3692 |
ISO 4762 |
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ISO 4014 |
ISO 4032 |
UNI 5931 |
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ISO 4017 |
ISO 4033 |
BS 2470 |
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BS 1769 |
ANSI B18.2.2 |
BS 4168 |
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BS 3692 |
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ANSI B18.2.1 |
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Socket & Slotted Set Screws |
Socket & Slotted Countersunk Screws |
Studs |
Washers |
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DIN 913 |
DIN 963 |
DIN 938 |
DIN 125 |
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DIN 914 |
DIN 7991 |
DIN 939 |
DIN 9021 |
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DIN 915 |
BS 4168 |
DIN 2510 |
BS 4320 |
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DIN 916 |
BS 1981 |
BS 4439 |
BS 3410 |
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DIN 551 |
BS 483 |
BS 2693 |
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DIN 553 |
BS 2470 |
Spring Washers |
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DIN 438 |
DIN 127 |
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BS 4168 |
BS 4464 |
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BS 1802 |
Alloy Steel Gr B7 Fasteners find extensive applications in high temperature and high-pressure usage owing to their superior strength and durability. They are used extensively across sectors like oil & gas, petrochemical, power generation, and construction. Alloy Steel Gr B7 Fasteners are suitable for applications involving pressure vessels, pipes, flanges, and valves in refineries as well as chemical plants. They are also used in heavy machinery, structural framing, and high-stress conditions where reliability is the primary concern. Their exceptional corrosion resistance and heat tolerance make them suitable for extreme conditions, offering safety and long-term reliability in severe industrial and engineering applications.
Marzouk Steel is a leading manufacturer, supplier and exporter of high-quality Carbon Steel, Alloy Steel, Mild Steel and Galvanized Steel products. Our extensive product range includes Pipes, Tubes, Flanges, Pipe Fittings, Forged Fittings, Sheets and Plates, catering to various industries in Tunis, Tunisia.
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