Threaded nails are nails that have a spiral "thread" or grooves on their shank. This design feature is key to providing superior holding power compared to smooth shank nails.
Here's a more detailed breakdown:
How Threaded Nails Work
The thread on a nail functions to:
- Spin During Installation: As the nail is driven into the material (typically wood), the threads cause it to rotate. This rotational motion effectively "screws" the nail into place.
- Create a Mechanical Interlock: The threads cut into the wood fibers as the nail is driven, creating a strong, thread-like interlock. This interlock significantly increases the nail's resistance to being pulled out (withdrawal resistance).
Advantages of Threaded Nails
- Increased Withdrawal Resistance: The primary advantage is their significantly greater holding power compared to smooth nails. This makes them ideal for applications where the joint is subject to tension or vibration.
- Easier Driving in Harder Woods: The spiral design also assists in easier penetration into harder woods and denser materials. The twisting action helps to displace the wood fibers, reducing the force required to drive the nail.
- Reduced Splitting: In some cases, the thread can help to reduce splitting, especially in brittle materials or when nailing close to the edge.
Types of Threaded Nails
While the fundamental principle remains the same, threaded nails come in various forms:
- Spiral Shank Nails: These feature a continuous spiral thread along the entire length (or most of the length) of the shank.
- Ring Shank Nails: These nails have a series of rings around the shank. While not a continuous thread, these rings also create a strong mechanical interlock.
Applications
Threaded nails are used in a wide range of applications, including:
- Decking: For securely fastening deck boards to joists.
- Flooring: For subflooring and hardwood flooring applications.
- Roofing: Certain types of roofing applications require nails with superior holding power.
- Framing: While not always necessary for general framing, they can be beneficial in areas subject to high wind or seismic activity.
- Pallet Construction: Threaded nails are commonly used to assemble pallets due to the strength requirements.
In summary, threaded nails are a type of fastener engineered with a spiral thread on their shank to increase holding power and resistance to withdrawal by creating a mechanical interlock with the material they are driven into.
