🔩 304 Stainless Steel Cap Nuts – Decorative Acorn Nuts for M3 to M12 Screws
Give your bolts a clean, finished look while protecting exposed threads from damage. These 304 stainless steel cap nuts (also called acorn nuts or dome nuts) slide over the end of a screw or bolt, hiding sharp edges and adding a polished, professional appearance. Made from high‑grade 304 stainless, they resist rust, corrosion, and daily wear — perfect for home furniture, outdoor equipment, automotive projects, and even marine applications. Available in metric sizes M3, M4, M5, M6, M8, M10, and M12. Whether you’re building a custom shelf, repairing a motorcycle, or finishing a food‑grade machine, these cap nuts deliver both function and style.
✨ Why Choose These 304 Stainless Steel Cap Nuts
Premium 304 stainless steel – Excellent corrosion resistance, rust‑proof, and durable. Holds its bright finish even in humid or outdoor environments.
Fine threading & smooth surface – Deep, uniform threads ensure a snug fit without cross‑threading. No burrs or sharp edges – safe to touch.
Decorative acorn shape – The domed top covers the end of the bolt completely, preventing snagged clothing or scratched surfaces. Adds a clean, professional look to any project.
Wide size range (M3 to M12) – Covers small electronics (M3) up to heavy‑duty machinery (M12). Each size matches standard metric screw threads.
Easy to install & remove – Use a standard wrench or socket. The hex base provides a solid grip without damaging the finish.
Multi‑industry application – Works for home decoration, furniture assembly, medical equipment, vehicle parts, boat accessories, industrial machinery, and food processing equipment.
💡 Pro tip: Use these cap nuts on exposed bolts for a child‑safe finish (no sharp threads sticking out). Also great for covering threaded rod ends on custom furniture or gym equipment.
💬 Frequently Asked Questions – Stainless Steel Cap Nuts
Are these cap nuts compatible with standard metric bolts?
Yes – M3 to M12 sizes match standard metric coarse threads. For example, an M6 cap nut fits any standard M6 bolt or threaded rod. Fine thread versions are not included; please verify your bolt’s thread pitch if you have a non‑standard fine thread application.
Will 304 stainless steel rust over time?
304 stainless is highly corrosion‑resistant for most indoor and outdoor use. It can develop minor surface discoloration in very salty coastal environments or prolonged contact with chlorides (like pool chemicals). For marine or extreme saltwater use, consider 316 stainless. But for everyday furniture, automotive, and workshop use, 304 is more than enough.
What’s the difference between a cap nut and a regular hex nut?
A cap nut has a closed, domed end that covers the bolt tip. A regular hex nut is open on both ends. The cap protects threads from damage, prevents snagging on clothing or skin, and gives a finished look. It’s also called an “acorn nut” because of its shape.
Can I use these in food processing equipment?
Yes – 304 stainless steel is commonly used in food industry applications because it resists corrosion and is easy to clean. The smooth, burr‑free surface also prevents bacteria traps. However, always follow local sanitation guidelines and verify that all components (including thread lubricants) are food‑safe.
Do I need a washer under the cap nut?
Not necessarily – cap nuts can be used directly on a bolted joint. However, adding a flat washer distributes clamping force and protects the surface underneath. For vibration‑prone applications, consider a lock washer between the cap nut and the work surface.
What size wrench do I need for M3/M4/M5/etc.?
Typical hex sizes: M3 uses 5.5mm wrench, M4 uses 7mm, M5 uses 8mm, M6 uses 10mm, M8 uses 13mm, M10 uses 16mm, M12 uses 18mm. Always check actual nut flats, but these are standard.