Cap Nuts
Cap nuts — also called acorn nuts — have a domed, closed top that covers the exposed end of a bolt for a finished appearance and a safe, snag-free edge. They’re used on railings, furniture, appliances, playground and pool equipment, and anywhere protruding threads would look unfinished or catch skin and clothing. Eugene Fastener & Supply stocks cap and acorn nuts in steel (zinc), 18-8 stainless, brass, nylon, and metric.
Choose stainless or brass for outdoor and decorative work, nylon where you need non-marring or non-conductive, and zinc steel for general indoor use. We sell by the piece or in bulk, cross-reference part numbers, and ship same day on orders placed before 2pm Pacific.
Cap & Acorn Nuts — Steel, Stainless, Brass & Nylon
Need cap nuts for a finished installation or a production run?
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Cap Nuts by Material
- Steel Cap/Acorn Nuts — zinc-plated, general indoor use.
- Stainless Cap/Acorn Nuts — 18-8 for outdoor and corrosion resistance.
- Brass Cap/Acorn Nuts — decorative and electrical.
- Nylon Cap/Acorn Nuts — non-marring, non-conductive.
- Metric Cap/Acorn Nuts — coarse pitch.
Cap Nut FAQ
What is the difference between a cap nut and an acorn nut?
They are the same fastener — a hex nut with a closed, domed top. "Acorn nut" describes the rounded acorn-like shape; "cap nut" describes the function of capping the bolt end. Both cover exposed threads for a finished, safe-edge look.
What are cap nuts used for?
To cover the exposed end of a bolt for appearance and safety — on railings, furniture, appliances, playground and pool equipment, and anywhere protruding threads would look unfinished or snag skin and clothing.
Do cap nuts come in stainless and brass?
Yes — we stock 18-8 stainless for outdoor and corrosion resistance and brass for decorative and electrical work, plus zinc steel, nylon, and metric.
How long a bolt do I need for a cap nut?
The bolt should not bottom out in the dome. Leave room so the threads fully engage without the bolt end hitting the closed top; if the bolt is too long, the nut will not seat. Ask us if you need help sizing.
Why Buy from Eugene Fastener
- Steel, stainless, brass, nylon, and metric cap/acorn nuts in one place.
- By the piece or in bulk, with cross-reference help.
- Since 1969 — serving Pacific Northwest industry for over 55 years.
Cap and acorn nuts finish off our bolts and pair with washers. Browse all nut types or contact our sales team for finishes or bulk pricing. Eugene Fastener & Supply — serving the Pacific Northwest since 1969.