Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
You’re restoring an antique clock, building a decorative wooden box, or working on a marine electrical panel – and you need screws that look as good as they perform. These M3 brass countersunk screws combine the classic warmth of brass with the practicality of a Phillips drive. The flat head sinks flush into a pre‑drilled countersink, leaving a smooth, snag‑free surface. Made from solid brass, they resist corrosion, offer good conductivity, and develop a beautiful natural patina over time. Fully threaded from 5mm up to 25mm length (under head). Perfect for woodworking, instrument repair, boat fittings, and any project where ordinary steel screws would look out of place.
| Thread Diameter | Length (under head, mm) | Overall Length (including head, approx.) | Fully Threaded |
|---|---|---|---|
| M3 | 5 | ~5.8mm | Yes |
| M3 | 6 | ~6.8mm | Yes |
| M3 | 8 | ~8.8mm | Yes |
| M3 | 10 | ~10.8mm | Yes |
| M3 | 12 | ~12.8mm | Yes |
| M3 | 16 | ~16.8mm | Yes |
| M3 | 20 | ~20.8mm | Yes |
| M3 | 25 | ~25.8mm | Yes |
📐 Length is measured from the underside of the head to the tip (grip length). All screws are fully threaded. Overall length includes the flat head (approx. +0.8mm).
| Parameter | Details |
|---|---|
| Product name | M3 Brass Phillips Countersunk Flat Head Machine Screws/Bolts |
| Material | Solid brass (leaded or unleaded – standard brass alloy) |
| Standard | Metric (GB/T equivalent to DIN/ISO) |
| Thread diameter | M3 (3mm nominal) |
| Length options | 5, 6, 8, 10, 12, 16, 20, 25 mm (under head) |
| Head style | Countersunk / Flat (90° cone) |
| Drive style | Phillips (cross recess) |
| Thread type | Metric coarse (0.5mm pitch), fully threaded |
| Corrosion resistance | Good – suitable for indoor and light outdoor use (forms protective patina) |
| Typical applications | Woodworking, furniture, instrument repair, marine hardware, electronics, vintage restoration |
1. Do I need to countersink the hole for these screws to sit flush?
Yes – for the head to be perfectly flush with the surface, you must drill a matching 90° countersink hole. Use a countersink bit slightly larger than the screw head diameter. In soft wood, you can sometimes tap the head in with a hammer, but proper countersinking gives a much cleaner result and prevents the wood from splitting.
2. Are these screws strong enough for furniture assembly?
Brass is softer than steel, so these screws are best for light to medium duty applications – think decorative hinges, small drawer pulls, instrument mounting, or electrical connections. For heavy structural loads (e.g., bed frames, shelving), use steel screws. For most furniture accents and light assembly, brass is perfectly adequate and looks beautiful.
3. Will brass screws rust or tarnish over time?
Brass does not rust (it contains no iron). It does develop a natural patina – first darkening, then sometimes turning greenish (verdigris) in humid or marine environments. Many people prefer this aged look for vintage projects. If you want to keep them shiny, apply a clear lacquer or polish periodically.
4. Can I use these screws in marine or outdoor applications?
Yes – brass is corrosion‑resistant in saltwater and fresh water, making it a good choice for boat fittings, dock hardware, and outdoor furniture. However, avoid direct contact with aluminum or galvanized steel in wet conditions, as galvanic corrosion can occur (brass is more noble). Use isolation washers or dielectric grease if mixing metals.
5. How do I measure the length of a countersunk screw?
For countersunk flat head screws, the length is measured from the underside of the head (the bearing surface) to the tip. The head itself is not included in the length. So an “M3 x 10mm” screw has a 10mm long threaded portion under the head. Our list follows this standard.
6. Do these screws come with matching brass nuts or washers?
This listing is for screws only. We also sell brass hex nuts and flat washers separately – check our store for M3 brass hardware. Using brass nuts with brass screws ensures no galvanic issues and a consistent appearance.
