Stainless Steel Nylock Acorn Cap Nut M4–M12 304 Dome Hex Self-Locking Locknut

Stainless Steel Nylock Acorn Cap Nut M4–M12 — 304 Dome Hex Self-Locking Locknut

304 stainless steel Nylock acorn dome cap nuts combine two functions in one fastener: the protective dome of an acorn cap nut that covers and shields exposed bolt ends, and the nylon insert of a nyloc nut that provides self-locking vibration resistance. This dual-function design is ideal for applications where both bolt end protection and anti-loosening performance are required — such as outdoor equipment, automotive builds, and safety-critical assemblies.

Key Specifications

Parameter	Value
Material	304 Stainless Steel
Locking Mechanism	Nylon insert (Nylock / nyloc)
Head Style	Dome cap (acorn / blind)
Thread Type	Metric coarse
Size Range	M4, M5, M6, M8, M10, M12
Drive	Hex (spanner / socket)

Why Choose Nylock Acorn Cap Nuts?

• Dual function — dome cap protects exposed bolt end from injury and corrosion; nylon insert provides self-locking vibration resistance in a single component
• Nylon insert locking — nylon collar deforms around bolt thread on installation, creating friction that resists loosening under vibration without damaging the thread
• 304 stainless steel — corrosion-resistant for outdoor, marine, and humid environments
• No separate lock washer needed — self-locking nylon insert eliminates the need for a separate lock washer or thread-locking compound
• M4–M12 range — covers light mechanical (M4–M6) through structural assembly (M8–M12)

Typical Applications

• Outdoor and playground equipment — covering sharp bolt ends for safety + vibration resistance
• Automotive and motorcycle custom builds — decorative dome cap with anti-loosening performance
• Marine and boat hardware — stainless dome cap protects bolt ends from saltwater corrosion
• Electronics enclosure assembly — covering internal bolt ends with anti-loosening protection
• Bicycle and e-bike component mounting (M5–M8)
• Industrial machinery with vibration exposure (M8–M12)

Compatible With

• Standard metric coarse thread bolts and studs M4–M12
• Spanner / socket: M4=7mm, M5=8mm, M6=10mm, M8=13mm, M10=17mm, M12=19mm AF
• Note: nylon insert limits maximum service temperature to approximately 120°C

Package Contents

• Nylock acorn dome cap nuts in selected size and quantity (per variant)

Frequently Asked Questions

Q: Can Nylock acorn cap nuts be reused?

A: Nyloc nuts lose some locking effectiveness each time they are removed and reinstalled, as the nylon insert deforms permanently on first use. For safety-critical applications, replace nyloc nuts after each removal. For non-critical applications, they can typically be reused 2–3 times if the nylon insert still provides resistance.

Q: What is the maximum temperature for the nylon insert?

A: The nylon insert has a maximum continuous service temperature of approximately 120°C. For higher temperature applications (e.g., near exhaust systems or power electronics), use an all-metal locking nut (prevailing torque nut) instead.

Q: How does a Nylock acorn nut differ from a standard acorn nut?

A: A standard acorn nut (DIN1587) has no locking mechanism and can loosen under vibration. A Nylock acorn nut adds a nylon insert that provides self-locking vibration resistance. Choose Nylock when both bolt end protection and anti-loosening performance are required.

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