M1.2–M6 Phillips Flat Head Machine Screws | Carbon Steel | Black & Nickel Plated

Match the diameter to your tapped hole or nut (e.g., M3 screw into an M3 threaded hole). For length, the screw should engage at least 1–1.5× the diameter in the base material. For example, an M3 x 10mm (≈3/8") screw typically works well for 3–6mm thick panels. When countersinking, the head should sit flush or just below the surface — measure your countersink depth before selecting length.

Carbon steel Phillips flat head machine screws are generally rated at property class 4.8 or higher, with tensile strength typically in the range of 420–800 MPa depending on size and heat treatment. For structural or safety-critical applications, contact us to confirm the specific grade before ordering.

The black oxide finish offers mild corrosion resistance suitable for indoor and low-humidity applications. The nickel-plated finish provides better moisture resistance and is generally more suitable for light outdoor or damp environments. For fully corrosive or marine conditions, stainless steel fasteners are typically recommended instead.

These screws follow the ISO metric thread standard (M-series). They are compatible with standard metric nuts, threaded inserts, and tapped holes of the corresponding size. They are not compatible with UNC/UNF (inch) threaded components. If you are unsure, check that your hardware is labeled with an M-size (e.g., M3, M4) rather than a fractional inch size.

Choose black oxide for a low-profile matte appearance, commonly used in electronics, machinery, and applications where a dark finish is preferred or required. Choose nickel plated for a brighter look with improved corrosion resistance, often used in consumer products, appliances, and visible hardware where appearance matters.

These screws use a Phillips (cross) drive. As a general guide: PH0 for M1.2–M1.6, PH1 for M2–M3, and PH2 for M4–M6. Using the correct bit size is important — an oversized bit can damage the head, while an undersized bit increases the risk of cam-out. Always use a well-fitting bit and apply steady downward pressure.

Yes. These machine screws are designed for use with pre-tapped holes or threaded inserts in a wide range of materials including plastic enclosures, aluminum extrusions, sheet metal, and steel brackets. They are not self-tapping — a matching threaded hole is required. For plastic, brass or stainless heat-set inserts are commonly used to create a durable threaded seat.