🔩 Product Overview: M4 & M5 Phillips Pan Head Screws with Washer – 304 Stainless Steel
No more hunting for a separate washer every time you grab a screw. These M4 and M5 Phillips pan head machine bolts come with matching washers included – so you're ready to bolt things down right out of the bag. Made from A2 (304) stainless steel, they offer excellent corrosion resistance for outdoor furniture, marine hardware, and humid environments. The rounded pan head gives a clean, low‑profile finish, while the Phillips drive works with standard #2 bits. Fully threaded to GB standards and rated Grade 5, these bolts are strong enough for light structural work, yet compact enough for appliances, electronics enclosures, and DIY repairs. Choose your length and get to work.
✨ Why Choose 304 Stainless Pan Head Screws with Washers
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A2 (304) stainless steel – Higher corrosion resistance than 201 stainless. Bright surface finish. Perfect for outdoor or humid environments – resists rust and acid.
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Includes matching washers – Each screw comes with a washer that distributes clamping force, prevents loosening from vibration, and protects soft surfaces like plastic or wood.
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Phillips pan head design – Rounded top with a flat bearing surface. Sits neatly on panels and distributes clamping force evenly.
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Metric sizes M4 and M5 – Versatile diameters for furniture assembly, machinery, automotive trim, and marine hardware.
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Fully threaded, GB standard coarse pitch – Threads run the entire shank length. M4x0.7, M5x0.8 for maximum grip in thin materials.
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Grade 5 strength – Reliable for general fastening in light structural and mechanical applications.
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Made in China, GB standard – Consistent quality and thread accuracy.
📏 Technical Specifications – M4 & M5 Pan Head Screws (304 Stainless)
| Specification |
M4 |
M5 |
| Thread Diameter (d) |
4mm |
5mm |
| Thread Pitch (p) |
0.7mm |
0.8mm |
| Head Style |
Pan head / Round head |
| Drive Style |
Phillips (PH2 recommended) |
| Material |
A2 (304) Stainless Steel |
| Washer Included |
Yes – matching flat washer per screw |
| Thread Type |
Fully threaded |
| Length Measurement |
Under head – see product options |
| Grade |
Grade 5 |
| Standard |
GB |
📊 Stainless Steel Comparison – Which Grade to Choose?
| Grade |
Corrosion Resistance |
Surface Brightness |
Best Use |
| 201 Stainless (SUS) |
Poor – rusts with water |
Dull, may have bubbles or pinholes |
Dry indoor decorative use only |
| 304 Stainless (A2) |
Good – resists corrosion & acid |
High brightness, clean finish |
Outdoor, humid, general purpose (these screws) |
| 316 Stainless (A4) |
Excellent – with molybdenum for saltwater & chemicals |
Bright |
Marine, coastal, high‑chloride areas |
❓ FAQs – M4/M5 Pan Head Screws with Washers (304 Stainless)
🔸 Are the washers separate or pre‑attached?
They come as separate flat washers alongside the screws. You slide the washer onto the screw before driving – this gives you the option to use the washer or not, depending on your surface. Both screw and washer are made of 304 stainless.
🔸 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 pan head. For example, an M5 x 20mm screw has a 20mm threaded shank below the head.
🔸 Will 304 stainless steel rust in outdoor or coastal environments?
304 stainless is highly resistant to moisture, rain, and humidity – perfect for most outdoor use. However, in coastal areas with high salt spray or chlorides, 316 stainless (A4) is recommended. For general outdoor furniture, garden equipment, and covered marine applications, 304 performs very well. These screws are ideal for humid environments.
🔸 What Phillips screwdriver size works for M4 and M5?
M4 uses a PH1 or PH2 (PH1 is often best). M5 uses a PH2. A good quality PH2 bit will handle both comfortably. Using the correct size prevents stripping.
🔸 Can I use these screws with nuts, or are they self‑tapping?
These are machine screws – they require a matching metric nut (M4 or M5) or a pre‑tapped hole. They are not self‑tapping. For best corrosion resistance, pair them with 304 stainless nuts.
🔸 How can I tell if these are genuine 304 stainless vs 201?
Genuine 304 has a brighter, cleaner surface and higher corrosion resistance. A simple test: 201 stainless will show rust spots quickly in humid conditions, while 304 will remain shiny. You can also use a stainless steel test solution – no color change indicates 304.
