M2 M2.5 M3 M4 Titanium Phillips Countersunk Screws – Flat Head Machine Bolts

Match the thread diameter to your tapped hole or threaded insert size (M2, M2.5, M3, or M4). For length, measure the total thickness of the material being fastened — the screw length should equal that thickness so the flat head sits flush with the surface. For example, a 6mm (≈1/4") thick panel typically calls for an M3 x 6mm screw. When in doubt, go one size longer and countersink slightly deeper. If threading into a blind hole, leave at least 1–1.5× the thread diameter of clearance at the bottom.

Titanium alloy fasteners generally offer tensile strength comparable to mid-grade alloy steel — typically in the range of 900–1000 MPa for Grade 5 / Ti-6Al-4V alloy — while weighing approximately 45% less than steel. Compared to 316 stainless steel, titanium is generally stronger per unit weight and more corrosion-resistant in most environments. Contact us to confirm the specific alloy grade and mechanical properties for your application.

Yes. Titanium alloy naturally forms a stable oxide layer that resists corrosion in saltwater, humid, and mildly acidic environments without any additional coating. These titanium flat head screws are a practical choice for outdoor electronics enclosures, marine hardware, cycling components, and other applications exposed to moisture and weather. For highly aggressive chemical environments, contact us to confirm suitability.

These screws follow the ISO metric coarse thread standard. M2 uses a 0.4mm pitch, M2.5 uses a 0.45mm pitch, M3 uses a 0.5mm pitch, and M4 uses a 0.7mm pitch. They are compatible with standard metric tapped holes, threaded inserts, and metric nuts of the same diameter and pitch. They are not compatible with UNC/UNF (inch) threads.

M2 and M2.5 screws typically use a PH0 (Phillips #0) driver. M3 screws typically use a PH1 (Phillips #1) driver. M4 screws typically use a PH2 (Phillips #2) driver. Always use a driver that fits snugly in the recess — a loose-fitting driver increases the risk of cam-out, which can damage the head. Apply firm downward pressure while driving to minimize slippage.

Yes. Titanium and aluminum have a low galvanic corrosion potential, making these screws a technically sound choice for aluminum frames, enclosures, and CNC-machined parts. They are also widely used in carbon fiber composite panels and rigid plastic assemblies. Use a calibrated torque wrench and follow the recommended torque specification for the thread size to avoid stripping the tapped hole, especially in softer materials. For plastic, consider using a threaded insert for best results.

For a single repair or prototype build, 10 or 20 pcs is generally sufficient. Workshop restocking or small production runs typically call for 30 pcs. For ongoing manufacturing, RC builds, or bicycle workshop use, 40 or 50 pcs offers a lower per-unit cost and reduces reorder frequency.