Serrated Flange Bolts Manufacturer
MT.BOLTS manufactures Serrated Flange Bolts, which are externally threaded fasteners featuring an integrated flange beneath the hex head, with serrations on the underside of the flange. These serrations help grip the mating surface, preventing loosening from vibration and eliminating the need for a separate washer. Serrated flange bolts are ideal for automotive, machinery, and structural applications where vibration resistance and high clamping force are essential. MT.BOLTS offers these bolts in various sizes, materials, and finishes to meet demanding mechanical and industrial requirements.
- System of Measurement:
Metric (M5–M24) | Imperial (1/4″ to 1″) - Length Range:
Metric: 10 mm to 150 mm
Imperial: 0.5″ to 6″ - Thread Pitch:
Metric (Coarse/Fine) | UNC/UNF - Thread Type:
Full or partial thread - Head Type:
Hex head with integrated serrated flange
Serrated Flange Bolts Material Types
MT.BOLTS supplies carbon steel, stainless steel, duplex steel, and nickel-based alloy Serrated Flange 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 |
Serrated Flange Bolts System of Measurement
- Metric Sizes: M5 to M24
- Imperial Sizes: 1/4″ to 1″
- Length Range:
- Metric: 10 mm to 150 mm
- Imperial: 0.5″ to 6″
- Thread Pitch: Metric (Coarse/Fine) | UNC/UNF
- Thread Type: Fully or partially threaded
Serrated Flange Bolts Common Standards
- DIN 6921 – Hex flange bolts with serration
- ISO 1665 – Hex flange bolts
- JIS B1189 – Japanese flange bolt standard
- ASME B18.2.1 – Inch series bolts (adapted for flange type)
Serrated Flange Bolts Surface Finishes
- Zinc-plated – Corrosion resistance in indoor environments
- Hot-dip galvanized – Excellent protection in outdoor/marine use
- Black oxide – Mild corrosion resistance, often for aesthetic or indoor use
- Passivated – Used on stainless steel bolts to improve corrosion resistance
- Custom Coatings (e.g., PTFE) – Non-stick, chemical-resistant for harsh environments
Why Choose MT.BOLTS
- Material Diversity
- Standardized Production
- Ample Inventory
- Competitive Pricing
- Low-MOQ Customization
Benefits and Limitations of Serrated Flange Bolts
Advantages
- Built-in washer distributes load over a larger area
- Serrations resist loosening under vibration
- Reduces need for separate lock washers
- Speeds up installation and improves clamping force
- Common in automotive and machinery applications
Disadvantages
- Serrations may damage soft mating surfaces
- Not suitable for applications requiring smooth contact areas
- Cannot be reused frequently due to wear on serrations
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Serrated Flange Bolts Applications
- Automotive assemblies (engine mounts, frames)
- Heavy machinery and equipment
- Construction and structural joints
- Vibratory systems and moving parts
- Agricultural and mining equipment
FAQ About Serrated Flange Bolts
The serrations grip the surface, preventing bolt loosening from vibration or torque.
Limited reuse is possible, but repeated tightening may wear out the serrations.
Yes, they integrate the function of a washer while also providing anti-loosening benefits.
They are not recommended for soft materials (e.g., plastics, soft aluminum) that can be damaged by serrations.
Yes, standard flange bolts without serrations are also common for applications requiring smooth contact.
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