M3 Nylon Phillips Countersunk Screws – White Plastic Machine Bolts

A general rule is to choose a length that allows the screw to penetrate the base material by at least 2–3 times the thread diameter. For M3 screws, that typically means at least 6–9mm of thread engagement in the base material. For example, if you're fastening a 4mm panel, a 10mm (≈3/8") screw generally provides solid grip. Note that length is measured including the head on countersunk screws — factor in your material thickness accordingly.

Nylon screws are generally lighter and more flexible than metal fasteners, making them well-suited for low-torque, non-structural applications. They typically handle tensile loads appropriate for light electronics assembly, PCB mounting, and enclosure work. For heavy structural loads or high-vibration environments, metal fasteners are generally recommended. Do not overtighten — nylon threads can strip more easily than metal under excessive torque.

Nylon is inherently corrosion-resistant and does not rust, making these screws generally suitable for damp or mildly wet environments. However, prolonged UV exposure can cause nylon to become brittle over time. For long-term outdoor use, consider protecting the fasteners from direct sunlight, or contact us to confirm suitability for your specific application.

These screws follow the ISO metric thread standard at M3 × 0.5mm pitch, which is the most common M3 thread pitch used worldwide. They are compatible with standard M3 metric nuts, M3 threaded brass inserts, and any M3-tapped hole machined to ISO standard. They are not compatible with UNC/UNF inch-standard threads.

These screws use a Phillips (cross) drive. A PH1 (Phillips #1) screwdriver or bit is typically the correct size for M3 Phillips screws. Using the correct bit size and applying steady downward pressure while turning helps prevent cam-out and protects the nylon head from stripping. Avoid power drivers set to high torque — hand-tightening or a low-torque setting is generally recommended for nylon fasteners.

Yes — the countersunk (flat) head is designed to sit flush with or below the surface when installed in a properly countersunk hole. The head angle is 90°, which is the standard for metric countersunk screws. Pre-drilling a countersink with a 90° countersink bit is recommended for a clean flush finish. Without a countersink, the head will protrude above the surface.

Yes. Nylon (PA66) is a non-conductive material, making these M3 nylon Phillips countersunk screws a common choice for electronics assembly, PCB mounting, and any application where electrical isolation between components is needed. They will not create short circuits or interfere with grounding paths the way metal screws can.