A Hi-Lok fastener is a two-part, high-strength fastener system primarily used in aerospace and other demanding applications where precise and consistent clamping force is critical. Although not technically a rivet in the traditional sense, it functions similarly in joining materials together.
Here's a more detailed breakdown:
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Two-Part System: A Hi-Lok fastener consists of two main components:
- A threaded pin: This pin has a specifically designed thread and a break-off groove.
- A collared nut: This nut features a wrenching surface and often has a self-locking mechanism.
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Consistent Torque: The key feature of Hi-Lok fasteners is their ability to provide consistent and controlled torque. As the nut is tightened onto the pin, a portion of the nut (the 'Hi-Lok' portion) breaks off at a predetermined torque level. This breakaway feature ensures that each fastener is installed with the correct clamping force, eliminating guesswork and potential over- or under-tightening.
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High Strength: Hi-Lok fasteners are made from high-strength materials like alloy steel or titanium, allowing them to withstand significant loads and stresses. This is crucial in aerospace applications where structural integrity is paramount.
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Applications: They are widely used in:
- Aircraft manufacturing
- Aerospace structures
- High-performance vehicles
- Other applications requiring reliable and repeatable fastening.
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Installation: Installation requires specific tooling to properly tighten the nut until the break-off occurs. This ensures the correct torque is applied.
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Advantages over Traditional Rivets:
- Consistent clamp load: Unlike traditional rivets which rely on operator skill to properly upset, Hi-Loks guarantee a specific torque.
- Higher strength: Generally stronger than traditional rivets.
- Ease of inspection: Easier to visually inspect proper installation (absence of the break-off portion).
In summary, a Hi-Lok fastener offers a precise, high-strength alternative to traditional rivets, particularly valuable in applications where consistent clamping force and reliability are essential.
