Which Screw Should I Use for Sheet Metal?
For fastening into sheet metal, you need a screw that can cut its own threads into the material. The two main options are self-tapping sheet metal screws and self-drilling (tek) screws.
Self-Tapping Sheet Metal Screws
These have a sharp point and coarse threads designed to cut into pre-drilled or punched holes in thin metal. You need a pilot hole first, then the screw taps its own threads as you drive it in. Available with hex washer head or pan head. Best for attaching panels, brackets, and trim to light-gauge steel, aluminum, or plastic.
Self-Drilling (Tek) Screws
Self-drilling screws have a built-in drill bit at the tip that eliminates the need for a pilot hole. They drill, tap, and fasten in one step — faster than self-tapping screws when working with heavier gauge metal. Commonly used in HVAC ductwork, metal roofing, and steel stud framing.
Head Styles
- Hex washer head: built-in washer face for better sealing and load spread. The most popular choice for sheet metal and HVAC.
- Pan head: lower profile, neater appearance. Used where a flush or clean look matters.
Why Stainless Steel?
If the sheet metal assembly will be exposed to moisture, weather, or corrosive chemicals, stainless steel screws prevent rust and extend the life of the fastened joint. All sheet metal screws on Fastenio are 18-8 stainless steel.
Quick Decision Guide
- Pre-drilled hole available: self-tapping sheet metal screw
- No pilot hole, heavier gauge metal: self-drilling tek screw
- HVAC / ductwork / roofing: hex washer head self-drilling
- Clean appearance: pan head