Acorn Nuts Manufacturer
MT.BOLTS manufactures Acorn Nuts, also known as Cap Nuts or Dome Nuts, which are specialized fastening components designed to provide a finished appearance and protect exposed bolt or screw threads. These nuts feature a smooth, rounded top that not only improves safety by eliminating sharp thread ends but also enhances corrosion resistance by sealing off the threaded portion from environmental exposure. MT.BOLTS offers acorn nuts in a variety of sizes, materials, thread types, and surface finishes to meet diverse mechanical, aesthetic, and protective requirements.
- System of Measurement:
- Metric: M6 – M64
- Imperial: 1/4″ to 2.5″
- Height Range (Overall Height):
- Metric: 10 mm to 70 mm
- Imperial: 3/8″ to 2-3/4″
(Height varies depending on dome style and thread size) - Thread Pitch:
- Metric: Coarse (default), Fine (on request)
- Imperial: UNC, UNF
- Thread Type:
- Right-hand thread (standard)
- Left-hand thread (optional)
- Nut Types:
- Standard Acorn Nut (Low Dome)
- High Acorn Nut (Extended Dome for longer threads)
- Self-locking Acorn Nut
- Decorative Acorn Nut (for furniture or display)
Acorn Nuts Material Types
MT.BOLTS supplies carbon steel, stainless steel, duplex steel, and nickel-based alloy Acorn Nuts , 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 |
Acorn Nuts System of Measurement
Acorn nuts are manufactured in both metric and imperial systems to suit global fastening applications:
Metric Sizes: M4 to M64
Imperial Sizes: 1/4″ to 2.5″
Overall Height Range:
Metric: 10 mm to 70 mm
Imperial: 3/8″ to 2-3/4″
Thread Pitch:
Metric: Coarse (standard), Fine available
Imperial: UNC, UNF
Thread Direction:
Right-hand thread (standard)
Left-hand thread (optional)
Acorn Nuts Common Standards
Acorn nuts are manufactured according to the following international and industry standards:
DIN 1587 – Metric cap nuts
ASME B18.2.2 – Inch-series cap nuts
ASTM A563 – Mechanical properties for carbon and alloy steel nuts
SAE J483 – Specifications for dome nuts used in automotive and general industry
ISO 4032 with dome variants – Metric thread compatibility
Custom / OEM specifications – For decorative, marine, or protective applications
Acorn Nuts Surface Finishes
A variety of surface coatings are available to meet aesthetic, corrosion, or environmental resistance needs:
Plain (uncoated) – For dry, indoor use
Zinc-plated (clear or yellow) – Moderate corrosion protection
Nickel-plated – Smooth, shiny, corrosion-resistant for visible fastenings
Hot-dip Galvanized – For structural and outdoor environments
Polished or Passivated Stainless Steel – Ideal for marine or hygiene-critical settings
Black Oxide – Decorative and light corrosion protection
Custom Coatings – PTFE, Geomet®, decorative colors, etc.
Why Choose MT.BOLTS
- Material Diversity
- Standardized Production
- Ample Inventory
- Competitive Pricing
- Low-MOQ Customization
Benefits and Limitations of Acorn Nuts
Benefits:
Thread Protection – Seals off exposed threads, preventing corrosion or damage
Safety Enhancement – Rounded dome reduces injury from sharp bolt ends
Aesthetic Finish – Provides a clean, finished appearance
Vibration Resistance – Some variants offer locking capabilities
Suitable for Decorative or High-Visibility Assemblies
Limitations:
Limited Thread Engagement – Not ideal for high-load applications unless matched properly
Size-Specific – Height must be adequate to cover full thread length
Higher Cost Than Standard Nuts – Especially in stainless or decorative finishes
Not Always Readily Available in All Grades or Coatings
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Acorn Nuts Applications
Acorn nuts are widely used across industries and applications that require thread protection, decorative finishes, or improved safety:
Automotive & Motorcycle Assemblies – Wheel studs, trim, covers
Furniture & Fixtures – Visible joints in furniture, railings
Machinery & Equipment – To protect operators from thread ends
Architectural & Decorative Metalwork – Railings, gates, ornamental fasteners
Electronics & Enclosures – Aesthetic bolt terminations
Marine & Outdoor Installations – Corrosion-resistant acorn nuts in stainless steel
FAQ About Acorn Nuts
Acorn nuts cover exposed bolt or stud ends to protect threads, improve safety, and enhance appearance.
Yes, but repeated use may affect thread integrity or dome fit, especially in plated versions.
They provide limited load-bearing capacity and are not ideal for high-tension joints unless properly matched.
Common materials include carbon steel, brass, stainless steel (304, 316), and decorative alloys.
Some variants include nylon inserts or thread deformation for vibration resistance.
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