🟡 Product Overview: Solid Brass M4 x 12mm Round Head Phillips Screws – GB/T818
Whether you're restoring a vintage radio, building a marine instrument, or just need a non‑magnetic, corrosion‑resistant fastener, these solid brass round head Phillips machine screws are a perfect fit. This listing is for M4 diameter, 12mm length – a common size for electronics enclosures, furniture hardware, and decorative trim. Manufactured by BRT Fasteners to GB/T818 standards, each screw has a protective oil coating to prevent tarnish during storage. The round (pan) head gives a clean, low‑profile finish, and the Phillips drive works with standard #1 or #2 bits. Length is measured under the head, so an M4 x 12mm screw has 12mm of threaded shank below the rounded top. Fully threaded with coarse pitch (M4x0.7), these brass screws are reliable, attractive, and ready to ship in plastic packaging.
✨ Why These Brass Round Head Phillips Screws Stand Out
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Solid brass construction – Naturally corrosion‑resistant, non‑magnetic, and non‑sparking. Perfect for electrical applications, boat hardware, and antique restoration.
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Round (pan) head design – Low‑profile rounded head with a flat bearing surface. Sits neatly on surfaces and gives a classic, finished look.
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Phillips drive – Works with standard #1 or #2 Phillips screwdrivers. Easy to install with common tools.
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GB/T818 standard – Precision head dimensions (dk = 6.5mm, k = 2.2mm for M4) and consistent thread geometry.
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Fully threaded, M4 coarse pitch (0.7mm) – Threads run the entire shank length, providing maximum grip in thin materials.
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Protective oil coating – A light oil film prevents tarnish during storage and handling. Wipe before use if desired.
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Plastic packaging – Keeps screws organized and protected for shipping.
📏 Technical Specifications – M4 x 12mm Brass Round Head Screws (GB/T818)
| Specification |
Details |
| Brand |
BRT Fasteners |
| Product Type |
Solid Brass Round Head Phillips Machine Screws |
| Standard |
GB/T818 |
| Material |
Brass (solid, unplated) |
| Surface Treatment |
Protective oils (light anti‑tarnish film) |
| Screw Size |
M4 (4mm thread diameter) |
| Thread Pitch |
0.7mm (standard metric coarse) |
| Thread Type |
Fully threaded |
| Length (under head) |
12mm (example – other lengths available separately) |
| Head Diameter (dk) |
6.5mm (per GB/T818) |
| Head Height (k) |
2.2mm (per GB/T818) |
| Packaging |
Plastic bag / plastic packaging |
📐 GB/T818 Head Dimensions Reference (for other sizes)
| Screw Size (d) |
Head Diameter (dk) |
Head Height (k) |
| M2 |
3.1mm |
1.1mm |
| M2.5 |
4.1mm |
1.5mm |
| M3 |
5.0mm |
1.7mm |
| M3.5 |
5.5mm |
2.0mm |
| M4 |
6.5mm |
2.2mm |
| M5 |
8.4mm |
2.9mm |
| M6 |
9.8mm |
3.4mm |
| M8 |
13.0mm |
4.5mm |
| M10 |
17.1mm |
6.0mm |
❓ FAQs – M4 Brass Round Head Phillips Screws
🔸 Are these screws fully threaded? How is length measured?
Yes – they are fully threaded from just under the head to the tip. Length is measured from the underside of the head (the flat bearing surface) to the tip, not including the round head. This M4 x 12mm screw has a 12mm threaded shank.
🔸 Will brass screws rust or tarnish over time?
Brass does not rust like steel. It may develop a darker patina or slight greenish tint (verdigris) over years in damp or salty environments. The protective oil coating delays tarnish during storage. For indoor use, they'll stay golden for a long time. For outdoor use, they outperform plain steel but aren't as corrosion‑resistant as stainless – ideal for decorative or low‑moisture exterior work.
🔸 What Phillips screwdriver size works best for M4 brass screws?
An M4 round head Phillips screw typically uses a PH1 or PH2 bit. PH1 gives better engagement in brass without overtightening. Use a quality driver to avoid cam‑out.
🔸 Can I use these screws with nuts, or are they self‑tapping?
These are machine screws – they require a matching M4 metric nut or a pre‑tapped hole. They are not self‑tapping. For best results, pair with brass or stainless steel M4 nuts.
🔸 Are M4 brass screws magnetic? Will they interfere with electronics?
Brass is completely non‑magnetic. That makes them perfect for sensitive electronic equipment, compass housings, or any application where stray magnetism is a problem.
🔸 Do you offer other lengths or sizes besides M4 x 12mm?
Yes – we stock other diameters (M2–M10) and lengths. Please check our store for additional listings or contact us for custom orders.
