Hex Head Screw Bolts Manufacturer
MT.BOLTS manufactures Hex Head Screw Bolts, which are externally threaded fasteners featuring a six-sided (hexagonal) head designed to be tightened using a wrench or socket. These bolts are among the most commonly used fastener types across a wide range of industries due to their versatility, high strength, and ease of installation. Whether used in structural assemblies, machinery, or corrosive environments, MT.BOLTS provides high-performance hex head bolts in a variety of materials, sizes, and standards to meet demanding engineering requirements.
- System of Measurement: Metric (M3–M64) | Imperial (#4 to 2.5″)
- Length Range: 6 mm to 500 mm | 0.25″ to 20″
- Thread Pitch: Metric (Coarse/Fine) | UNC/UNF
- Thread Type: Full or partial thread
- Head Type: Standard Hex | Heavy Hex
- Finish Options: Plain, passivated, or customer-specified
- Standards:
- ASME B18.2.1 (Inch Hex Bolts)
- ASME B18.2.3.1M (Metric Hex Bolts)
- DIN 933 / DIN 931 (ISO 4017 / ISO 4014)
Hex Head Screw Bolts Material Types
MT.BOLTS supplies carbon steel, stainless steel, duplex steel, and nickel-based alloy hex head screw bolts, meeting the demanding requirements of chemical, marine, and high-temperature environments, compliant with various international standards.
| Material Category | Common Grades/Models | Description |
| Carbon Steel | ASTM A307, A325, A490 | High strength and cost-effective, suitable for general structures; requires anti-corrosion coating. |
| Stainless Steel | 304 (A2), 316 (A4), 321, 410 | Excellent corrosion resistance; widely used in food, chemical, and construction industries |
| Duplex Stainless Steel | UNS S31803/S32205 (F51), UNS S32750 (F53) | High strength with superior chloride corrosion resistance; used in seawater, petrochemical, and paper industries |
| Monel Alloys | Monel 400, Monel K500 | Excellent seawater corrosion resistance and mechanical strength; used in marine engineering and pump systems |
| Hastelloy Alloys | Hastelloy C276, C22, B2, X | Excellent resistance to strong acids and oxidizing media; widely used in chemical equipment and flue gas desulfurization |
| Inconel Alloys | Inconel 600, 625, 718 | Resistant to high temperature, pressure, and corrosion; used in heat exchangers, aerospace, and nuclear industries |
| Incoloy Alloys | Incoloy 800, 825, 925 | Ideal for high-temperature acidic environments; widely used in petroleum refining and heat treating systems |
| Nickel Alloys | Nickel 200, 201 | Pure or high-nickel alloys with excellent conductivity and alkali resistance; used in electronics and chemical applications |
Hex Head Screw Bolts System of Measurement
- Metric: M3 to M64 (commonly M6, M8, M10, M12, M16, M20, M24)
- Imperial/Inch: #4 to 2.5″, including UNC (Unified Coarse Thread) and UNF (Unified Fine Thread)
Hex Head Screw Bolts Common Standards
| Standard | Description |
| ASME B18.2.1 | Hex head bolts per ASME specification |
| ASME B18.3 | Hex socket (Allen) bolts standard |
| ISO 4014 / 4017 | Partially/fully threaded hex bolts |
| DIN 933 / 931 | Fully/partially threaded hex bolts (German standard) |
| ASTM A193 / A320 | High-strength bolts for high/low temperature applications |
Hex Head Screw Bolts Surface Finishes
| Surface Finish | Description |
| Plain (Uncoated) | No coating, suitable for stainless steel or indoor use |
| Zinc Plated | Economical corrosion protection, available in clear or yellow zinc |
| Hot-dip Galvanized | Thick zinc coating for outdoor structures, wind towers, and bridges |
| Black Oxide | Attractive appearance, mild corrosion resistance; used in machinery and vehicles |
| PTFE / Xylan Coated | Excellent anti-corrosion, anti-seize, and wear resistance; ideal for chemical environments |
| Passivated | For stainless steel only; enhances natural corrosion resistance |
Wrench Size Chart
| Bolt Diameter (Metric) | Wrench Size (mm) | Bolt Diameter (Inch) | Wrench Size (inch) |
| M6 | 10 | 1/4″ | 7/16″ |
| M8 | 13 | 3/8″ | 9/16″ |
| M10 | 17 | 1/2″ | 3/4″ |
| M12 | 19 | 5/8″ | 15/16″ |
| M16 | 24 | 3/4″ | 1-1/8″ |
| M20 | 30 | 1″ | 1-5/16″ |
Why Choose MT.BOLTS
- Material Diversity
- Standardized Production
- Ample Inventory
- Competitive Pricing
- Low-MOQ Customization
Benefits and Limitations of Hex Head Screw Bolts
Advantages
- High torque tightening capability with excellent shear strength
- Compatible with multiple tools (hex, socket, pneumatic)
- Secure fastening for high-load applications
- Versatile and widely available
- Easy to install and remove for maintenance
Disadvantages
- The head is exposed and not suitable for flush installation
- Requires more space; not ideal for tight spaces
- Needs surface coating or corrosion-resistant materials in harsh environments
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Hex Head Screw Bolts Applications
- Structural steel connections (beams, columns)
- Heavy machinery (presses, pumps)
- Automotive manufacturing and repair
- Oil and gas platforms and wellheads
- Chemical vessels and heat exchangers
- Wind turbine tower connections
- Marine and port infrastructure
FAQ About Hex Head Screw Bolts
Hex cap screws typically have tighter tolerances and may feature a washer face under the head; hex bolts are more general-purpose.Hex cap screws typically have tighter tolerances and may feature a washer face under the head; hex bolts are more general-purpose.
Yes, they are commonly used with flat washers, lock washers, and hex nuts for secure fastening.
No special tools are needed—standard wrenches, sockets, or impact drivers work effectively.
Full-thread provides better grip in short lengths; partial-thread bolts offer better shear strength in longer or structural applications.
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