Marzouk Steel, headquartered in Tunis, Tunisia, is a trusted manufacturer and supplier of premium steel products, catering to industries that require strength, precision, and durability. Among its specialized offerings are Alloy Steel GR 12.9 Fasteners, designed for high-strength, high-performance, and critical mechanical applications. Manufactured with advanced technology and stringent quality control, GR 12.9 fasteners deliver exceptional tensile strength, hardness, and reliability. Marzouk Steel ensures that every GR 12.9 fastener meets international standards, providing engineers and fabricators with a dependable solution for automotive, heavy machinery, petrochemical, and industrial systems requiring secure, high-performance fastening.
Alloy Steel GR 12.9 Fasteners are made from high-grade alloy steel with precise heat treatment, engineered for superior tensile strength, hardness, and fatigue resistance. Their chemical composition, including carbon, chromium, and molybdenum, enhances toughness, impact resistance, and wear resistance. GR 12.9 fasteners provide excellent mechanical properties, including extremely high yield strength and tensile strength, making them ideal for critical applications requiring secure fastening under extreme stress. With consistent performance and long-term reliability, these fasteners ensure safety and durability in demanding industrial and mechanical environments.
Standard :Â DIN EN ISO 4014 & 4017 DIN 931 / 933 & IS 1364 / IS 1363
Size :Â Dia M 20 to 100 mm / Inch 3/4″to 3.1/2″
Finish :Â Plain / Zinc plated / Hot dip galvanised
Types :Â Nuts, Bolts, Screws, Sockets, Studs, Screw, Hex Set Screw, Socket Screw, Cap Screw, Pan Head Screw, Socket Head Cap Screw, Washers, Spring Washers, Studs, Anchors
| Grades | Size Range | PS [MPa] | YS (min) [MPa] | TS (min) [MPa] | Hardness [Rockwell] |
| Class 12.9 | Under M16 | 580 | 640 | 800 | |
| 17-72 | 600 | 660 | 830 | C23–34 |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
Hexagon Bolts / Set Screws | Stud Bolts | Hexagon Nuts | Socket Capscrews |
|---|---|---|---|
DIN 931 | BS4882 | DIN 934 | DIN 912 |
DIN 933 | DIN 976 | BS 1768 | DIN 6912 |
BS 1768 | Â | BS 1769 | DIN 7984 |
UNI 5731 | Â | BS 1083 | ANSI B18.3 |
UNI 5739 | Â | BS 3692 | ISO 4762 |
ISO 4014 | Â | ISO 4032 | UNI 5931 |
ISO 4017 | Â | ISO 4033 | BS 2470 |
BS 1769 | Â | ANSI B18.2.2 | BS 4168 |
BS 3692 | Â | Â | Â |
ANSI B18.2.1 | Â | Â | Â |
Socket & Slotted Set Screws | Socket & Slotted Countersunk Screws | Studs | Washers |
DIN 913 | DIN 963 | DIN 938 | DIN 125 |
DIN 914 | DIN 7991 | DIN 939 | DIN 9021 |
DIN 915 | BS 4168 | DIN 2510 | BS 4320 |
DIN 916 | BS 1981 | BS 4439 | BS 3410 |
DIN 551 | BS 483 | BS 2693 | Â |
DIN 553 | BS 2470 | Â | Spring Washers |
DIN 438 | Â | Â | DIN 127 |
BS 4168 | Â | Â | BS 4464 |
 |  |  | BS 1802 |
Alloy Steel GR 12.9 Fasteners are widely used in industries requiring extremely high-strength and reliable fastening solutions. They are commonly applied in heavy machinery, automotive assemblies, construction equipment, petrochemical plants, and industrial machinery subjected to high stress and vibration. Engineered to withstand extreme loads, cyclic stresses, and harsh operating environments, GR 12.9 fasteners provide secure and long-lasting connections. Engineers and fabricators rely on these fasteners for critical applications where durability, safety, and operational efficiency are essential. Their combination of tensile strength, hardness, and fatigue resistance ensures dependable performance in demanding industrial and mechanical environments.
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.
Copyright 2025 Marzouk Steel. All rights reserved
