Product Overview
The Acorn Nut, also known as a Cap Nut or Dome Nut, is a one-piece, closed-end fastener designed to provide both a finished appearance and functional protection at the end of a threaded bolt or stud. Its domed, acorn-shaped head fully encapsulates the exposed threads, enhancing safety, preventing snagging, and shielding the threads from dirt, moisture, and corrosion. It is widely used in applications where aesthetics, safety, and cleanliness are priorities.
Key Advantages
Safety & Protection: Encloses sharp or protruding threads, preventing injury (anti-snag) and protecting threads from damage and environmental contamination.
Enhanced Aesthetics: Provides a smooth, rounded, finished look, ideal for visible or consumer-facing applications.
Corrosion Barrier: Seals the thread end, helping to prevent internal corrosion of the stud or bolt.
One-Piece Design: More robust and reliable than two-piece acorn cap assemblies, with no risk of the cap detaching.
Versatile Fastening: Can be used with or without a washer and is suitable for both adjustment points and final terminations.
Material Specifications & Grades
| Material Standard | Grade / Alloy | Characteristics & Typical Uses |
|---|---|---|
| Low/Medium Carbon Steel | Grade 5 / 8 (Quenched & Tempered) | General purpose, high strength. Commonly plated for corrosion protection. |
| Stainless Steel | ASTM A304 (A2) / 316 (A4) | Excellent corrosion resistance for marine, food processing, and architectural applications. |
| Brass | C36000 (Free-Cutting) | Decorative, good corrosion resistance, non-sparking, and non-magnetic. |
| Aluminum | 6061-T6 | Lightweight, good corrosion resistance, and anodizable for color matching. |
| Nylon / Plastic | PA6, PA66 | Excellent electrical insulation, chemical resistance, and light weight. No rust. |
Product Series & Standards
Standard Acorn Nuts: Compliant with dimensional standards such as ASME B18.2.2 and DIN 1587.
High (Deep) & Low (Shallow) Dome Profiles: Available depending on the required thread coverage and aesthetic preference.
Drive Types: Most feature an internal hex drive (ISO 4762 socket) for installation. Some smaller sizes may have an external hex base.
Thread Sizes: Metric: M3 to M24. Imperial: #4-40 to 1″-8.
Finish: Available with a smooth dome or a knurled perimeter for easier hand-tightening.
Available Surface Finishes
| Finish Type | Specification / Process | Appearance & Key Property |
|---|---|---|
| Zinc Plated (Blue, Clear, Yellow Chromate) | ASTM B633 | Silvery to iridescent/yellow. Standard corrosion protection. |
| Chrome Plated (Decorative) | – | Bright, mirror-like finish. High luster for decorative hardware. |
| Electroplated Nickel | ASTM B456 | Bright satin silver. Good tarnish and wear resistance. |
| Black Oxide / Phosphated | MIL-DTL-13924 | Matte black. Mild corrosion resistance, reduces glare. |
| Passivation (Stainless Steel) | ASTM A967 | Maintains the natural metallic look of stainless steel; enhances corrosion resistance. |
| Anodized (Aluminum) | MIL-A-8625 | Clear or colored (e.g., black, gold). Excellent corrosion/abrasion resistance and color options. |
| Powder Coated | – | Wide range of colors (RAL, custom). Thick, durable, decorative finish. |
Quality Assurance
Our Acorn Nuts are manufactured under a certified ISO 9001:2015 quality management system. Production includes dimensional inspection to ensure proper thread fit (Go/No-Go gauging) and dome integrity. Material certificates are available for traceability.
Manufacturing Expertise
Produced by Hebei Wohe Fastener Manufacturing Co. Ltd., our acorn nuts are formed using precision cold-heading technology for consistent material density and strength. Our manufacturing process, supported by expertise in multi-station forming and threading, ensures a high-quality finish both internally and on the visible dome surface, meeting the demands of furniture, automotive, RV, and general hardware industries.
Availability: A wide range of standard sizes and finishes are available.
Customization: Options include custom colors (powder coat/anodize), special engravings/logos, and non-standard thread sizes.
MOQ: Standard items start from 2,000 pieces. Custom orders are negotiable.
Lead Time: Standard inventory: 10-15 days. Custom finishes/sizes: 20-30 days.
Note: For hand-tightened applications, a knurled edge version is recommended. Always ensure the thread length of the mating stud is less than the internal depth of the acorn nut to achieve full closure. Specifications are subject to change without notice.
