Self Thread Screws also known as self-tapping screws are designed to drill their own holes in materials like wood, metal and plastic, creating precise threads without pre-drilled holes.

Self-tapping screws are versatile fasteners primarily used to join materials where only one side is accessible. They are commonly used in metal, wood, and plastic applications and are particularly useful for roofing, furniture assembly, and various construction projects. 
Here's a more detailed look at their uses:

1. Joining Materials from One Side: Self-tapping screws are ideal when you can't access the back of the material for a bolt and nut. This is common in situations like attaching metal roofing sheets or securing components in furniture. 
2. Metal Applications: 
Construction: Self-tapping screws are widely used in metal framing, cladding, and roofing.
Automotive and Manufacturing: They are essential for assembling various components in these industries.
HVAC: They are used for ductwork, brackets, and other components.
3. Woodworking: 
Quick Assembly:
Self-tapping screws are convenient for quickly joining wooden pieces, especially in furniture construction.
Softer Woods:
They are often used in softer woods where pre-drilling a pilot hole may not be necessary.
4. Plastics:
Component Assembly:
Self-tapping screws can be used to assemble plastic components and products. 
Specific Plastics:
They are particularly useful with materials like fiberglass and polycarbonate. 
5. Other Uses:
Brick and Masonry:
Some self-tapping screws are designed for use with brick and masonry, often with a pilot hole. 
Surgical Implants:
Interestingly, self-tapping screws are also used in medical applications like orthopedic bone screws. 
Key Considerations:
Pilot Holes:
While some self-tapping screws can create their own threads (thread-cutting), others (thread-forming) require a pre-drilled pilot hole. 
Material Compatibility:
Different types of self-tapping screws are designed for specific materials, so it's important to choose the right one. 
Sharpness:
Self-tapping screws typically have sharp threads that cut into the material, allowing them to grip securely.