Types of Screws by Material and How to Choose the Right One
Screws are essential components used to fasten or assemble various materials such as metal, plastic, wood, and concrete. However, screws are not just categorized by size or shape; they must be selected according to the material being worked on. Choosing the right screw for the material ensures both work efficiency and structural safety.
In this blog post, we’ll explore which types of screws are suitable for different materials. We’ll cover the characteristics of each material, the most appropriate screws, and what to consider when choosing one.
1. Screws for Metal
Metals are hard and non-deforming, so screws need high strength and precise threading. Typically, machine screws or tapping screws are used for metals.
- Machine Screws: Used for threaded metal holes
- Tapping Screws: Create threads in unthreaded metal
- Hex Bolts: Used for structural or heavy-duty fastening
- Stainless Steel Screws: Ideal for rust resistance
For soft metals like aluminum, choose screws with finer threads to prevent material damage.
2. Screws for Wood
Wood is fibrous and can split or deform easily. Therefore, screws with deep threads and wide pitch are recommended, usually with pointed tips.
- Wood Screws: Sharp ends and deep threads for grip
- Lag Bolts: For large wood joints without nuts
- Drywall Screws: For securing drywall to wood studs
Pre-drilling is recommended to prevent cracking. Choose screws depending on the type of wood—softwood or hardwood.
3. Screws for Plastic
Plastics are prone to deformation and cracking. Therefore, use screws designed to distribute pressure evenly and always use low-speed drivers.
- Plastic Tapping Screws: Wide pitch and low thread profile
- PT Screws (Triangular Thread): For high retention with minimal stress
- Self-Tapping Screws: Create threads without pre-cutting
For strong plastics like ABS or polycarbonate, stainless or brass screws are recommended. Adjust insertion depth and torque carefully.
4. Screws for Concrete or Masonry
Concrete and stone are hard but brittle. Anchors or specialized screws are essential, and pre-drilling is required.
- Concrete Anchor Bolts: Used with plugs or sleeves
- Tapcon Screws: Direct use after pre-drilling into concrete
- Sleeve Anchors: For mounting heavy objects
Use a hammer drill for pre-drilling, and match the hole diameter and depth exactly. Mistakes can severely reduce holding strength.
5. Screws for Composites and Special Materials
Composite materials like carbon fiber, fiberglass, and fiberboards are sensitive to vibration and fatigue. Screws should spread stress and maintain low pressure on the surface.
- Low-Pressure Screws: With shallow threads for stress dispersion
- Truss Head Screws: Wide heads to spread load evenly
- Screws with Built-in Washers: Prevent scratching and misalignment
Be cautious with rotation speed and insertion depth, and conduct tests before full application. For vibration-prone applications, use locking screws.
6. Conclusion: Always Match Screws to the Material
Choosing screws isn’t just about size—it’s about understanding the material’s properties and stress response. Different materials like wood, metal, plastic, and concrete respond differently to pressure and deformation, and screw designs reflect that.
Though small in size, the right screw can make a huge difference in durability and performance. Always analyze the material and application before choosing your fastener, and your project will be both safe and efficient.
