M2-M5 Button Head Socket Cap Screws ISO 7380 | Alloy Steel

A general rule is that the screw should engage at least 1.5× the thread diameter into the receiving material. For example, an M3 screw (3mm / ≈1/8\u201d diameter) should typically thread at least 4.5mm (≈3/16\u201d) deep. Available lengths range from 4mm (≈5/32\u201d) to 35mm (≈1-3/8\u201d). When in doubt, choose a length that allows full thread engagement without bottoming out in a blind hole.

These button head socket cap screws are generally manufactured from Grade 10.9 alloy steel, which typically provides a tensile strength of approximately 1040 MPa. This makes them suitable for medium-to-high load applications in mechanical assemblies. Please contact us to confirm the exact grade for your specific size before use in load-bearing or safety-critical applications.

Alloy steel is not inherently corrosion-resistant. For outdoor, humid, or chemically exposed environments, we recommend applying a protective coating (e.g., anti-seize compound) or selecting stainless steel alternatives. In most cases, uncoated alloy steel screws are best suited for indoor, dry, or protected applications.

These screws conform to ISO 7380 with ISO metric coarse thread (ISO 68-1). They are compatible with standard metric nuts, threaded inserts, and tapped holes in the corresponding metric sizes. They are not compatible with UNC or UNF inch-standard threads. If you are unsure, check that your existing hardware is labeled with an \u201cM\u201d designation (e.g., M3, M4).

The required hex key (Allen wrench) size varies by thread diameter: M2 → 1.5mm, M2.5 → 2mm, M3 → 2.5mm, M4 → 3mm, M5 → 4mm. Always use a properly fitting, good-quality hex key to avoid rounding the socket, especially on smaller sizes like M2 and M2.5.

Button head screws have a wider, lower-profile dome head compared to standard socket cap (SHCS) screws. This distributes clamping load over a larger bearing surface and keeps the head closer to the workpiece — ideal when head clearance is limited or when a snag-free, low-profile surface is needed. Common applications include electronics enclosures, robotics frames, 3D-printer builds, and furniture hardware.

Yes. The M2–M5 size range and low-profile head make these screws well-suited for aluminum extrusion T-slot frames, FDM 3D-printed parts, and plastic enclosures. When threading into softer materials, apply torque conservatively — generally 30–50% of the rated steel-to-steel torque — to avoid stripping threads. Using threaded inserts (e.g., heat-set inserts for plastics) is recommended for repeated assembly and disassembly.

Packs of 5 or 10 are ideal for one-off repairs or prototyping. Packs of 20 or 50 suit small production runs or workshop stock for a single project. Packs of 100 offer the best per-unit value for ongoing production, bulk restocking, or when you need a reliable supply of a frequently used size on hand.