Skip to content
Close
SEARCH
CONTACT
PHONE HOTLINE: 800-346-4296 E-MAIL: sales@hayn.com
Contact Us
PHONE HOTLINE: 800-346-4296 E-MAIL: sales@hayn.com
Contact Us
Hayn Product Header (2240 x 660 px) (7)

Cap (Acorn) Nuts

Hayn Cap (Acorn) Nuts are 18-8 stainless steel domed end nuts available in four thread sizes from 1/4-28 through 1/2-20, providing a clean, finished appearance at the exposed thread end of cable rail termination studs in both Concealed Thread and Traditional cable rail systems. 

Strong Where It Matters

Cap (Acorn) Nuts

Where a standard hex nut leaves a flat face and exposed thread stub at the post, the acorn nut's domed cap covers the thread end completely — a small detail that makes a visible difference on exterior decks, interior stair rails, and anywhere the termination hardware is viewed up close. Available in right hand thread only across four sizes covering 1/4-28, 5/16-24, 3/8-24, and 1/2-20, they are compatible with the full range of Hayn Concealed Thread and Traditional cable rail termination stud systems. For flat hex nut options in the same thread range, see the Hayn Hex Nut System. 
Request specifications
cap-nut

Cap / Acorn Nuts

Part # Thread Size Hand
14CAP 1/4-28 RH
516CAP 5/16-24 RH
38CAP 3/8-24 RH
12CAP 1/2-20 RH

Cap / Acorn nuts are 18-8 grade stainless steel and available in right hand thread only.

Engineered In America Every Hayn fitting is designed and manufactured at our facility in Rocky Hill, Connecticut — the same American workmanship that has set the standard for stainless steel rigging hardware since 1950.
Cold-Worked Production Hayn fittings are cold-worked, not cast. That distinction matters: the cold-working process refines grain structure, increases fatigue resistance, and produces a fundamentally stronger component — one built to perform when the load comes on it.
Precision Manufacturing Our Rocky Hill production floor runs CNC vertical mills, CNC lathes, large-capacity mill-turn centers, and waterjet cutting systems — all configured to produce hardware that meets exact specifications, every time.
75+ Years of Excellence Hayn has been engineering and manufacturing marine and architectural rigging hardware since 1950. That track record isn't just history, it's the design knowledge, failure data, and continuous improvement that goes into every product we make. 
  • Type 316 stainless steel construction for superior saltwater corrosion resistance
  • Manufactured in Rocky Hill, Connecticut to Hayn's proprietary tolerances
  • Precision-machined using advanced CNC manufacturing equipment



  • Engineered for seamless integration in marine and architectural rigging systems

  • Short lead times on both standard and custom components

  • Backed by 75 years of marine and architectural hardware expertise

More Products & Information

Hayn Product Header (2)

Let's Build Something Together

 Hayn has been engineering precision rigging hardware since 1950. So whatever your project demands, you're building with hardware that's been proven at sea and on structure for generations. 
Request Technical Specifications