M2‑0.40 x 4mm Button Socket Cap Screw – Class 10.9, Black Oxide, ISO 7380

This M2‑0.40 x 4mm button socket cap screw is manufactured from Class 10.9 alloy steel and produced to ISO 7380 standards for consistent strength and precision fit. The slightly longer length provides improved thread engagement for secure fastening in small‑scale assemblies, while the low‑profile button head offers a clean appearance in tight or visible applications. Finished with a thermal black oxide coating, it delivers reduced glare, mild corrosion resistance, and a professional, technical finish ideal for electronics, instrumentation, and light mechanical use.