M3.5 / M4 Countersunk Hex Socket Screws — Anodized Aluminum Alloy, 10 Colors

A general rule: screw length should be roughly 2–3× the screw diameter for most materials. For M3.5 screws, lengths of 6mm (1/4") to 16mm (5/8") typically cover thin panels and electronics enclosures. For M4 screws, 6mm (1/4") to 30mm (1-3/16") covers most DIY and light mechanical applications. Always account for the countersink depth when measuring your required grip length.

Anodized aluminum screws are generally suited for light-duty fastening — electronics, RC models, camera rigs, and decorative panels. They are not recommended for structural or high-torque applications where steel fasteners are typically required. Contact us to confirm suitability for your specific load requirements.

The anodized coating provides a layer of corrosion resistance, making these screws generally suitable for light outdoor exposure and humid environments. For prolonged submersion or highly corrosive conditions (e.g., saltwater or chemical exposure), stainless steel fasteners are typically recommended instead.

These screws follow the ISO metric thread standard (M3.5 and M4). They are compatible with standard metric nuts, threaded inserts, and tapped holes of the corresponding size. They are not compatible with imperial (UNC/UNF) threads. If you're unsure, check whether your existing hardware is labeled in millimeters (metric) or inches (imperial).

M3.5 countersunk hex socket screws typically require a 2mm or 2.5mm hex key. M4 screws generally use a 2.5mm or 3mm hex key. We recommend doing a test fit before final assembly to confirm the correct key size for your specific variant.

Yes — these are commonly used in aluminum extrusions, acrylic and polycarbonate panels, RC car and drone chassis, electronics enclosures, and lightweight structural frames. The countersunk head sits flush with the surface for a clean, professional finish. Ensure the receiving material is pre-drilled and countersunk to the correct angle (typically 90°) for best results.

The anodized color is purely aesthetic and does not affect mechanical performance. All color variants use the same aluminum alloy base and anodizing process. Available colors include black, silver, royal blue, sky blue, green, purple, wine red, peach-pink, golden yellow, and brown-orange. Many builders match screw color to their chassis or panel for a polished, coordinated look.

Each set contains 5 screws only — nuts and washers are not included. If you need matching metric nuts or washers, please browse our other listings or contact us for bundle options.