Filiz Steel, a reputable industrial supplier located in Istanbul, Turkey, proudly presents its top-notch **Carbon Steel 12.9 Fasteners**. These fasteners are specifically engineered for **high-stress and precision applications** where exceptional strength and performance are essential. Falling under ISO property class 12.9, they are crafted from **high-strength alloy carbon steel** and undergo a rigorous **quenching and tempering** process to maximize their mechanical capabilities. With their **remarkably high tensile strength and hardness**, 12.9 fasteners are perfect for demanding sectors such as **aerospace, automotive, heavy engineering, die and mold tooling**, and **structural steel assembly**.
These fasteners boast a **minimum tensile strength of 1220 MPa** and a **minimum yield strength of 1100 MPa**, positioning them among the strongest fastener classes on the market. Typically available as **socket head cap screws, bolts, and studs**, they often feature corrosion-resistant coatings like **zinc plating, black oxide**, or **phosphate finishes** to ensure durability even in tough environments. Their impressive hardness also provides excellent resistance to wear, fatigue, and shear, especially under dynamic or high-load conditions.
| Carbon Steel 12.9 | C | P | S | B |
| 0.28-0.5 | 0.025 | 0.025 | 0.003 |
| Nominal thread diameter size range [mm] | Proof strength [MPa] | Yield strength (min) [MPa] | Tensile strength (min) [MPa] | Hardness [Rockwell] |
| 1.6–100 | 970 | 1100 | 1220 | C39–44 |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
You’ll find 12.9 fasteners commonly used in **critical bolted joints**, **automotive drive components**, **machine tool assemblies**, and **precision equipment**—the go-to choice when safety, load retention, and structural integrity are paramount. Filiz Steel guarantees that all 12.9 grade fasteners meet international quality standards, including **ISO 898-1, DIN 912, ASTM**, and **BS**, with complete certification and traceability available for industrial and engineering needs.
| DIA | M4 | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | M42 | M45 | M48 | M52 |
| Pitch | 0.7 | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 | 3.5 | 4 | 4.5 | 5 | ||||||||
| Grade A upto length | 40 | 50 | 60 | 80 | 100 | 120 | 140 | 150 | Grade A not applicable to these dia’s | ||||||||||||
| Head Across Flat (S) Nom = Max Min Grade A Grade B | 7 | 8 | 10 | 13 | 16 | 18 | 21 | 24 | 27 | 30 | 34 | 36 | 41 | 46 | 50 | 55 | 60 | 65 | 70 | 75 | 80 |
| 6.78 | 7.78 | 9.78 | 12.73 | 15.73 | 17.73 | 20.67 | 23.67 | 26.67 | 29.67 | 33.38 | 35.38 | Grade A not applicable to these dia’s | |||||||||
| 6.64 | 7.64 | 9.64 | 12.57 | 15.57 | 17.57 | 20.16 | 23.16 | 26.16 | 29.16 | 33 | 35 | 40 | 45 | 49 | 53.8 | 58.8 | 63.1 | 68.1 | 73.1 | 78.1 | |
| Head Height (K) Nom Tol + or – Grade A Grade B | 2.8 | 3.5 | 4 | 5.3 | 6.4 | 7.5 | 8.8 | 10 | 11.5 | 12.5 | 14 | 15 | 17 | 18.7 | 21 | 22.5 | 25 | 26 | 28 | 30 | 33 |
| 0.125 | 0.15 | 0.18 | 0.215 | Grade A not applicable to these dia’s | |||||||||||||||||
| 0.2 | 0.24 | 0.29 | 0.35 | 0.42 | 0.5 | ||||||||||||||||
| Across corners e Min Grade A Grade B | 7.66 | 8.79 | 11.05 | 14.38 | 17.77 | 20.03 | 23.36 | 26.75 | 30.14 | 33.53 | 37.72 | 39.98 | Grade A not applicable to these dia’s | ||||||||
| 7.5 | 8.63 | 10.89 | 14.2 | 17.59 | 19.85 | 22.78 | 26.17 | 29.56 | 32.95 | 37.29 | 39.55 | 45.2 | 50.85 | 55.37 | 60.79 | 66.44 | 71.3 | 76.95 | 82.6 | 88.25 | |
| Major Dia at thread (min) | 3.838 | 4.826 | 5.794 | 7.76 | 9.732 | 11.701 | 13.682 | 15.682 | 17.623 | 19.623 | 21.623 | 23.577 | 26.577 | 29.522 | 32.522 | 35.465 | 38.465 | 41.437 | 44.437 | 47.399 | 51.399 |
| Major Dia at thread (max) | 3.978 | 4.976 | 5.974 | 7.972 | 9.968 | 11.966 | 13.962 | 15.962 | 17.958 | 19.958 | 21.958 | 23.952 | 26.952 | 29.947 | 32.947 | 35.94 | 38.94 | 41.937 | 44.937 | 47.929 | 51.929 |
| Thread Length (b) For lengths < or = 125mm For lengths > 125mm <= 200mm For lengths > 200mm | 14 | 16 | 18 | 22 | 26 | 30 | 34 | 38 | 42 | 46 | 50 | 54 | 60 | 66 | Not specified as full thread recommended | ||||||
| 20 | 22 | 24 | 28 | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | 66 | 72 | 78 | 84 | 90 | 96 | 102 | 108 | 116 | |
| 33 | 35 | 37 | 41 | 45 | 49 | 53 | 57 | 61 | 65 | 69 | 73 | 79 | 85 | 91 | 97 | 103 | 109 | 115 | 121 | 129 | |
Carbon Steel 12.9 fasteners are extensively used in processes where superior strength and durability are needed. They are best suited for high-stress situations, like automotive, aerospace, and heavy machinery sectors, where they hold key parts under severe conditions. Carbon Steel 12.9 fasteners are also used in construction projects, such as bridges and structural supports, as a result of their capacity to support heavy loads. In manufacturing, they are often applied in assembling industrial machines and equipment. Their resistance to wear and high tensile strength render them crucial in marine uses, oil and gas sectors, and power plants.
Filiz 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 Istanbul, Turkey.
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