🌊 Product Overview: M2–M8 A4 Stainless Steel Phillips Countersunk Screws – Marine Grade (DIN 965)
If you're building or repairing anything that touches saltwater – boats, docks, coastal furniture – you need fasteners that won't corrode after one season. These A4 (316) stainless steel Phillips countersunk machine screws are marine grade, with added molybdenum for superior resistance to chlorides, salt spray, and harsh chemicals. The flat 90° head sits flush in countersunk holes for a smooth, professional finish, while the Phillips drive works with standard bits for easy installation. Fully threaded to DIN 965 standards, available in diameters from M2 to M8 and lengths from 3mm to 100mm (length includes the head). Perfect for ship assembly, marine equipment, chemical plants, and outdoor DIY where rust is not an option.
✨ Why A4 (316) Marine Grade Countersunk Screws Are Worth the Upgrade
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A4 stainless steel (316 / marine grade) – Contains molybdenum for exceptional resistance to saltwater, chlorides, and industrial chemicals. Outperforms 304 in harsh marine and coastal environments.
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Phillips countersunk flat head – Sits flush in tapered holes for a snag‑free, professional surface. Ideal for decking, panels, and flush assemblies.
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DIN 965 standard – Precision head dimensions and consistent thread geometry. Fully threaded with coarse metric pitch.
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Wide size range: M2, M2.5, M3, M4, M5, M6, M8 – From tiny electronics and instruments up to structural marine hardware. One product line covers most needs.
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Lengths from 3mm to 100mm (including head) – Short screws for thin panels, long ones for thick assemblies. Choose exactly what your project requires.
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Easy to use with uniform force – Phillips drive provides good engagement, reduces slipping, and makes installation quick and convenient.
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Wide application range – Home and office appliances, communication equipment, ship assembly, furniture, car and motorcycle repair, industrial and construction fasteners, and DIY inventions.
📏 Technical Specifications – A4 Countersunk Phillips Screws (DIN 965)
| Specification |
Details |
| Product Type |
Phillips Countersunk Flat Head Machine Screws (DIN 965) |
| Material |
A4 Stainless Steel (316 / marine grade) |
| Grade |
A4 (316) – superior corrosion & acid resistance |
| Drive Style |
Phillips cross‑head |
| Head Style |
Countersunk / Flat head (90°) |
| System of Measurement |
Metric |
| Standard |
DIN 965 |
| Thread Sizes (Diameter) |
M2, M2.5, M3, M4, M5, M6, M8 |
| Thread Pitch (coarse) |
M2x0.4, M2.5x0.45, M3x0.5, M4x0.7, M5x0.8, M6x1.0, M8x1.25 |
| Thread Type |
Fully threaded |
| Length Range |
3mm – 100mm (length includes the head – total screw length) |
| Finish |
Natural stainless steel (unplated, bright) |
| MPN |
DIN 965 |
📊 Stainless Steel Comparison – Which Grade to Choose?
| Grade |
Corrosion Resistance |
Best Use |
| 201 Stainless |
Poor – rusts with water |
Dry indoor decorative use only |
| 304 Stainless (A2) |
Good – resists corrosion & acid |
Outdoor, humid, general purpose |
| 316 Stainless (A4) |
Excellent – with molybdenum for saltwater & chemicals |
Marine, coastal, high‑chloride areas (these screws) |
❓ FAQs – A4 Marine Grade Countersunk Screws
🔸 What’s the difference between A2 (304) and A4 (316) stainless steel?
A4 (316) contains molybdenum, which greatly improves resistance to chlorides – that means saltwater, de-icing salts, and many industrial chemicals. A2 (304) is fine for most indoor and general outdoor use, but A4 is the standard for marine, coastal, and chemical environments. It costs a bit more but lasts much longer in harsh conditions.
🔸 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 including the head (total screw length) – standard for countersunk fasteners. For example, an M5 x 20mm screw is 20mm long overall from the top of the flat head to the tip. Countersunk holes should be drilled to match this total depth.
🔸 Will A4 stainless steel rust in saltwater?
A4 (316) stainless is highly resistant to saltwater corrosion and is the go‑to choice for boat hardware, dock fittings, and submerged applications. While no metal is completely immune to crevice corrosion in stagnant, low‑oxygen conditions, 316 performs excellently for most marine use. Rinse occasionally with fresh water for maximum lifespan.
🔸 What Phillips screwdriver size works for M2 through M8?
M2–M2.5: use PH0 or PH00. M3–M4: use PH1. M5–M6: use PH2. M8: use PH2 or PH3 (PH2 works for most). Using the correct size prevents stripping.
🔸 Can I use these screws with nuts, or are they self‑tapping?
These are standard machine screws – they require a matching metric nut (M2–M8) or a pre‑tapped hole. They are not self‑tapping. For best corrosion resistance, pair them with A4 stainless nuts.
🔸 Are these screws magnetic?
A4 (316) stainless is generally non‑magnetic in its annealed state, but cold forming (like thread rolling) can make it slightly magnetic. A light magnetic response is normal and does not affect corrosion resistance.