Phillips Modified Truss Head Self-Tapping Screws M2–M4 | 304 Stainless Steel | Sheet Metal & Wood

A general rule is to select a length that penetrates the base material by at least 2/3 of the screw’s total length. For example, when fastening a 3mm panel, a screw of 6mm (≈1/4") or longer is typically recommended. For thin sheet metal under 1.5mm, shorter lengths such as 4mm–6mm are generally sufficient. Available lengths range from 4mm (≈5/32") to 20mm (≈3/4") — see variant options above.

A modified truss head (also called a mushroom head or wide round head) has a wider, lower-profile dome compared to a standard pan head. The larger bearing surface distributes clamping force over a greater area, reducing pull-through risk on thin sheet metal and soft wood. It is generally preferred when the fastening surface is soft or when a larger contact footprint is needed without using a separate washer.

304 stainless steel self-tapping screws generally provide good tensile strength for light to medium-duty fastening in sheet metal, wood, and similar materials. They are not typically rated for heavy structural loads. For high-stress or high-vibration applications, a larger diameter or a higher-grade fastener is generally recommended.

Yes. 304 stainless steel offers good corrosion resistance suitable for most outdoor and humid indoor environments, and is generally resistant to rust under normal atmospheric conditions. For marine or highly corrosive environments, 316 stainless steel is typically the recommended choice.

Yes. These use a standard Phillips (cross) drive compatible with PH0, PH1, or PH2 bits depending on the screw diameter. Smaller sizes such as M2–M2.3 typically use PH0 or PH1 bits, while M2.6–M4 generally use PH1 or PH2. Any standard manual or power screwdriver with the correct bit size will work.

For thin sheet metal, these self-tapping screws are generally designed to cut their own threads without pre-drilling. For wood applications, a pilot hole is typically recommended to prevent splitting, especially in hardwoods or near the edge of a workpiece. The pilot hole diameter should be slightly smaller than the screw’s thread diameter.

For thin sheet metal (under 2mm), M2–M2.6 screws with shorter lengths (4–10mm) are typically used. For light wood panels and composite boards, M3–M4 with lengths of 10–20mm are generally more appropriate. Always verify the material thickness and required holding strength before selecting a size.