Carbon Steel Bolts are tough and dependable fasteners that play a crucial role in connecting materials across mechanical, construction, and industrial settings. Crafted from high-quality carbon steel, these bolts boast impressive tensile strength, durability, and resistance to wear and deformation, even under heavy loads. With their precise threading and consistent dimensions, they ensure a secure fit and long-lasting performance. You’ll find Carbon Steel Bolts in applications where strength and reliability are non-negotiable, making them perfect for structural assemblies, machinery, automotive parts, and various construction projects.
Carbon steel bolts consist mainly of iron (Fe) with varying amounts of carbon (C), typically 0.05%–0.90%, affecting strength and hardness. Other constituents are manganese (Mn) 0.30%–1.65% for toughness, phosphorus (P) ≤0.04% and sulfur (S) ≤0.05% for machinability. Bolts possess good tensile strength (400–1,200 MPa), yield strength (250–1,000 MPa), and hardness (Rockwell B70–C45) based on the grade. Bolts exhibit excellent ductility, fair wear resistance, and poor corrosion resistance. Low-carbon varieties provide versatility, and high-carbon varieties provide greater strength and durability. Their mechanical characteristics make them fit for demanding industrial, automotive and construction applications requiring strong fastening solutions.
Specification : ASTM F568 / ASME SF568
Dimension : DIN, ISO, ASTM, JIS, BS, GB, IS and all International Standards
Size Range : M3 – M56 | 3/6″ to 2″ | Custom Sizes
Length : 3 mm to 200 mm
Type : Hex Head Bolts, Square Bolts, U bolts, Eye bolts, T bolt, Hex Bolt, Lag Bolts, Counter sunk Bolts
| Grade | C | P | S | B |
| Carbon Steel 10.9 | 0.20-0.55 | 0.025 | 0.025 | 0.003 |
| Carbon Steel 12.9 | 0.28-0.5 | 0.025 | 0.025 | 0.003 |
| Element | Nominal thread diameter size range [mm] | Proof strength [MPa] | Yield strength (min) [MPa] | Tensile strength (min) [MPa] | Hardness [Rockwell] |
| Carbon Steel 10.9 | 5–100 | 830 | 940 | 1040 | C32–39 |
| Carbon Steel 12.9 | 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.
These bolts are mainly made of iron, with a carefully controlled amount of carbon, plus small traces of manganese, sulfur, and phosphorus. The carbon content gives them high hardness and tensile strength, while still allowing enough ductility for easy threading and installation. Mechanically, they can handle significant shear and tensile forces, making them a reliable choice for moderate to heavy-duty tasks. Plus, heat treatment can enhance their hardness and strength for specific needs.
| Heavy Hex Bolt Diameter | D | F | C | H | |||||
| Body Diameter | Width Across Flats | Width Across Corners | Height | ||||||
| Max | Basic | Max | Min | Max | Min | Basic | Max | Min | |
| 1/2 | 0.515 | 7/8 | 0.875 | 0.850 | 1.010 | 0.969 | 11/32 | 0.364 | 0.302 |
| 5/8 | 0.642 | 1-1/16 | 1.062 | 1.031 | 1.227 | 1.175 | 27/64 | 0.444 | 0.378 |
| 3/4 | 0.768 | 1-1/4 | 1.250 | 1.212 | 1.443 | 1.383 | 1/2 | 0.524 | 0.455 |
| 7/8 | 0.895 | 1-7/16 | 1.438 | 1.394 | 1.660 | 1.589 | 37/64 | 0.604 | 0.531 |
| 1 | 1.022 | 1-5/8 | 1.625 | 1.575 | 1.876 | 1.796 | 43/64 | 0.700 | 0.591 |
| 1-1/8 | 1.149 | 1-13/16 | 1.812 | 1.756 | 2.093 | 2.002 | 3/4 | 0.780 | 0.658 |
| 1-1/4 | 1.277 | 2 | 2.00 | 1.938 | 2.309 | 2.209 | 27/32 | 0.876 | 0.749 |
| 1-3/8 | 1.404 | 2-3/16 | 2.188 | 2.119 | 2.526 | 2.416 | 29/32 | 0.940 | 0.810 |
| 1-1/2 | 1.531 | 2-3/8 | 2.375 | 2.300 | 2.742 | 2.622 | 1 | 1.036 | 0.902 |
| 1-3/4 | 1.785 | 2-3/4 | 2.750 | 2.662 | 3.175 | 3.035 | 1-5/32 | 1.196 | 1.054 |
| 2 | 2.039 | 3-1/8 | 3.125 | 3.025 | 3.608 | 3.449 | 1-11/32 | 1.388 | 1.175 |
| 2-1/4 | 2.305 | 3-1/2 | 3.500 | 3.388 | 4.041 | 3.862 | 1-1/2 | 1.548 | 1.327 |
| 2-1/2 | 2.559 | 3-7/8 | 3.875 | 3.750 | 4.474 | 4.275 | 1-21/32 | 1.708 | 1.479 |
| Nominal or Basic Product Diameter | E | F | G | H | J | LT (Thread Length) | Y | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Body Diameter | Width Across Flats | Width Across Corners | Head Height | Wrenching Height | For Bolt Lengths | For Bolt Lengths | Transition Thread Length | ||||||||
| 1/4 | 0.25 | 0.25 | 0.245 | 7/16 | 0.438 | 0.428 | 0.505 | 0.488 | 5/32 | 0.163 | 0.150 | 0.106 | 0.750 | 1.000 | 0.250 |
| 5/16 | 0.3125 | 0.3125 | 0.3065 | 1/2 | 0.500 | 0.489 | 0.577 | 0.557 | 13/64 | 0.211 | 0.195 | 0.140 | 0.875 | 1.125 | 0.278 |
| 3/8 | 0.375 | 0.375 | 0.369 | 9/16 | 0.562 | 0.551 | 0.650 | 0.628 | 15/64 | 0.243 | 0.226 | 0.160 | 1.000 | 1.250 | 0.312 |
| 7/16 | 0.4375 | 0.4375 | 0.4305 | 5/8 | 0.625 | 0.612 | 0.722 | 0.698 | 9/32 | 0.291 | 0.272 | 0.195 | 1.125 | 1.375 | 0.357 |
| 1/2 | 0.5 | 0.5 | 0.493 | 3/4 | 0.750 | 0.736 | 0.866 | 0.840 | 5/16 | 0.323 | 0.302 | 0.215 | 1.250 | 1.500 | 0.385 |
| 9/16 | 0.5625 | 0.5625 | 0.5545 | 13/16 | 0.812 | 0.798 | 0.938 | 0.910 | 23/64 | 0.371 | 0.348 | 0.250 | 1.375 | 1.625 | 0.417 |
| 5/8 | 0.625 | 0.625 | 0.617 | 15/16 | 0.938 | 0.922 | 1.083 | 1.051 | 25/64 | 0.403 | 0.378 | 0.269 | 1.500 | 1.750 | 0.455 |
| 3/4 | 0.75 | 0.75 | 0.741 | 1-1/8 | 1.125 | 1.100 | 1.299 | 1.254 | 15/32 | 0.483 | 0.455 | 0.324 | 1.750 | 2.000 | 0.500 |
| 7/8 | 0.875 | 0.875 | 0.866 | 1-5/16 | 1.312 | 1.285 | 1.516 | 1.465 | 35/64 | 0.563 | 0.531 | 0.378 | 2.000 | 2.250 | 0.556 |
| 1 | 1 | 1 | 0.99 | 1-1/2 | 1.500 | 1.469 | 1.732 | 1.675 | 39/64 | 0.627 | 0.591 | 0.416 | 2.250 | 2.500 | 0.625 |
| 1-1/8 | 1.125 | 1.125 | 1.114 | 1-11/16 | 1.688 | 1.631 | 1.949 | 1.859 | 11/16 | 0.718 | 0.658 | 0.461 | 2.500 | 2.750 | 0.714 |
| 1-1/4 | 1.25 | 1.25 | 1.239 | 1-7/8 | 1.875 | 1.812 | 2.165 | 2.066 | 25/32 | 0.813 | 0.749 | 0.530 | 2.750 | 3.000 | 0.714 |
| 1-1/2 | 1.5 | 1.5 | 1.488 | 2-1/4 | 2.250 | 2.175 | 2.598 | 2.480 | 15/16 | 0.974 | 0.902 | 0.640 | 3.250 | 3.500 | 0.833 |
You’ll often see Carbon Steel Bolts in construction frameworks, machinery assemblies, automotive manufacturing, industrial equipment, and structural supports. They’re great for fastening metal, wood, and composite materials in situations that demand secure and durable connections. Thanks to their strength, reliability, and resistance to mechanical stress, Carbon Steel Bolts are the go-to option for safe and long-lasting fastening solutions in industrial, commercial, and engineering applications.
Chetak 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 Hyderabad, India.
Copyright 2025 Chetak Steel. All rights reserved
