🔩 M3 Countersunk Thin Machine Screws – Carbon Steel, Nickel or Black Zinc, Phillips Drive (L3–16mm Lengths)
You’re fixing a laptop bottom cover, securing a small PCB, or assembling a delicate electronic device – and you need a screw that sits flush, won’t rust, and drives easily. These M3 countersunk screws are made from carbon steel with a choice of nickel or black zinc plating, giving you excellent corrosion resistance for indoor and light outdoor use. The flat 90° head sinks perfectly into a pre‑drilled countersink, leaving a smooth, snag‑free finish. The Phillips drive works with standard crosshead screwdrivers or power tools. Available in lengths from 3mm up to 16mm (overall length including head). Fully threaded. Perfect for electronics, mechanical equipment, automotive trim, and furniture hardware.
✨ Key Features – M3 Thin Countersunk Machine Screws
- 🔽 Countersunk flat head (90°) – Flush fit prevents snagging, ideal for slim devices and hidden fastening.
- 🧪 Nickel or black zinc plating – Choose bright nickel for a classic silver look or black zinc for a matte, low‑glare finish. Both provide corrosion resistance.
- 💪 Carbon steel core – High hardness and good tensile strength. Phillips drive for easy installation with hand or power tools.
- 📏 M3 metric thread (3mm diameter) – Popular size for laptops, tablets, small appliances, and light machinery.
- 📐 Lengths 3mm to 16mm (overall including head) – Example: M3 x 6mm means total length from top of head to tip is 6mm. Fully threaded.
- 🔧 Widely used – Electronics (motherboards, laptop casings), mechanical equipment (motor covers, control panels), automotive (ECU boxes, dashboard brackets), and furniture (hinges, drawer slides).
📏 Available Sizes – M3 Countersunk Screws (Overall Length)
| Thread Diameter (M) |
Overall Length (mm) * |
Thread Pitch (mm) |
Head Style |
Drive |
Finish Options |
| 📐 Length = from top of head to tip (total screw length). Fully threaded. Select exact size and finish from dropdown. |
| M3 |
3, 4, 5, 6, 8, 10, 12, 16 |
0.5 |
Countersunk / flat (90°) |
Phillips |
Nickel plated / Black zinc plated |
* Other lengths may be available – please contact us. Also available in M1, M1.2, M1.4, M1.7, M2, and M4 – select from dropdown or inquire.
📋 Which Finish Should You Choose?
| Finish |
Appearance |
Corrosion Resistance |
Best For |
| Nickel plated |
Bright silver, slightly shiny |
Good – indoor use, light moisture |
Electronics, visible fasteners, appliances |
| Black zinc plated |
Matte black, low glare |
Moderate – indoor use, light moisture |
Automotive trim, industrial equipment, dark assemblies |
❓ Frequently Asked Questions – M3 Countersunk Thin Screws
1. How do I measure the length of a countersunk screw?
For countersunk screws, the length is measured overall – from the top of the head to the tip. So an “M3 x 6mm” screw has a total length of 6mm including the head. This matches our listing.
2. Do I need to countersink the hole for these screws to sit flush?
Yes – these are true 90° countersunk screws. To achieve a flush finish, drill a matching 90° countersink hole. In soft plastics or thin wood, you can gently tap the head in, but proper countersinking gives the best result.
3. Are these screws fully threaded?
Yes – all M3 screws in this range are fully threaded from under the head to the tip, ensuring maximum grip even in shallow holes.
4. Will the plating rust? Can I use these screws outdoors?
Nickel and black zinc plating provide moderate corrosion resistance – fine for indoor use and occasional light outdoor exposure (e.g., covered patio). For continuous outdoor or marine environments, we recommend stainless steel screws. For most electronics and furniture applications, plated carbon steel is perfectly adequate.
5. What Phillips screwdriver size do I need for M3 screws?
Use a #0 or #1 Phillips screwdriver. A #0 fits smaller recesses better, but a #1 will also work. Always use a driver that fits snugly to avoid cam‑out and head damage.
6. Do you offer other diameters like M2 or M4?
Yes – we also carry M1, M1.2, M1.4, M1.7, M2, and M4 in the same style. Please select from the dropdown or contact us for custom orders.
