🔩 M2–M10 Phillips Flat Head Countersunk Machine Screws – 304 Stainless Steel, Metric
Need a screw that sits flush with the surface and stays rust‑free? These Phillips flat head countersunk machine screws are made from 304 stainless steel – strong, corrosion‑resistant, and perfect for furniture, electronics, automotive trim, and outdoor gear. The 90° countersunk head seats neatly into tapered holes, leaving a smooth, snag‑free finish. Available in diameters from M2 (tiny) up to M10 (heavy duty), with lengths from 4mm to 100mm (overall length including head). No more rusty screws ruining a clean project – grab the exact size you need.
✨ Why These Phillips Flat Head Screws Are a Workshop Staple
8 popular metric diameters – M2, M2.5, M3, M4, M5, M6, M8, M10. Covers everything from small electronics to heavy machinery.
304 stainless steel construction – Excellent rust and corrosion resistance. Works indoors, outdoors, and even in humid environments like kitchens or bathrooms.
Countersunk (flat) 90° head – Sits flush with the material surface when used with a countersunk hole. Ideal for door hinges, flush panels, and any application where a protruding head would catch or look messy.
Phillips drive for universal compatibility – Works with any Phillips screwdriver (#0 to #3 depending on size). No special bits needed.
Wide length range (4–100mm overall) – Total length includes the head. Choose from many lengths to suit your material thickness.
Versatile applications – Used in furniture making, industrial equipment, auto trim, boat fittings, electronics enclosures, and general home repair.
💡 Installation tip: Drill a countersunk hole (90° taper) for the head to sit flush. In soft materials like wood, you can use a countersink bit after drilling the pilot hole. In metal, use a stepped or single‑flute countersink.
📏 Specifications – M2–M10 Phillips Flat Head Countersunk Screws
| Parameter |
Details |
| Material |
304 stainless steel (A2) – corrosion resistant, non‑magnetic (slightly magnetic after cold forming) |
| Head Style |
Flat head (countersunk, 90° included angle) |
| Drive Type |
Phillips cross‑head |
| Thread Sizes (Diameter) |
M2, M2.5, M3, M4, M5, M6, M8, M10 (metric coarse thread) |
| Thread Pitch Range |
0.4mm (M2) up to 1.5mm (M10) – standard coarse pitch |
| Length Range (Overall) |
4mm to 100mm – total length includes the head |
| Measurement System |
Metric |
| Standard |
GB (Chinese national standard, compatible with DIN/ISO countersunk screws) |
| Applications |
Furniture, industrial machinery, electronics, automotive, marine, DIY |
📌 Example: M4×20mm means thread diameter 4mm, total length 20mm (including head). For other specifications (e.g., fine thread, longer lengths), feel free to contact us.
💬 Frequently Asked Questions – Countersunk Stainless Steel Screws
What’s the difference between countersunk (flat head) and pan head screws?
Countersunk screws have a tapered underside (usually 90°) that sits flush with the surface when driven into a matching tapered hole. Pan heads are domed and sit above the surface. Use countersunk when you need a smooth, snag‑free finish – like on door hinges, flush panels, or furniture where screws might catch clothing. Use pan head when you don’t want to countersink the hole or need a stronger clamping area.
Does the length measurement include the head or just the threaded portion?
For these flat head countersunk screws, the length listed is the total overall length – from the top of the head to the tip. That’s standard for countersunk screws because the head is part of the flush surface. So an M4×20mm screw will measure 20mm total. This is different from pan head screws, where length is usually measured under the head.
Will these rust if used outdoors or near the ocean?
304 stainless offers good corrosion resistance for most outdoor applications – rain, humidity, and even mild coastal spray. For permanent saltwater immersion (e.g., boat hulls below the waterline), we recommend 316 stainless. For typical garden furniture, outdoor signs, or deck hardware, 304 is perfectly fine and will not rust like ordinary steel.
What size Phillips screwdriver do I need for each M size?
General guide: M2–M2.5 use PH0, M3–M4 use PH1, M5–M6 use PH2, M8–M10 use PH3. Using the correct size reduces cam‑out and prevents stripping the head. Always use a quality driver that fits snugly.
Can I use these screws with nuts, or only into tapped holes?
Both work. These are standard machine screws, so they’re designed to be used with matching metric nuts or into pre‑tapped holes. For through‑hole applications, pair with a countersunk washer (or flat washer) and a nut. Do not drive them into hard materials without tapping – they are not self‑tapping.
Do you offer longer lengths or other sizes not listed?
Yes – we stock many additional lengths and can also source fine thread or custom sizes. Please contact us via the “Ask a question” tab with your specific requirements. We’re happy to help with bulk or custom orders.
