🌊 Product Overview: M2 & M2.5 Pozidriv Countersunk Machine Screws – A4 Stainless Steel (316 Marine Grade)
When you need a fastener that combines the flush finish of a countersunk head with the superior torque transfer of Pozidriv drive, these A4 stainless steel machine screws are the answer. Made from premium 316 stainless steel (A4 grade), they offer enhanced resistance to chlorides, acids, saltwater, and extreme temperatures – outperforming standard A2 (304) in marine and chemical environments. The 90° flat head sinks flush into countersunk holes, leaving a smooth, tamper‑resistant surface. Fully threaded with standard coarse metric pitch, available in M2 and M2.5 diameters. Perfect for micro‑engineering, medical devices, marine electronics, consumer electronics, optics, and aerospace applications where corrosion resistance and precision are critical.
✨ Why A4 Stainless Pozidriv Countersunk Screws Are the Premium Choice
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A4 stainless steel (316 / marine grade) – Contains molybdenum for exceptional resistance to saltwater, chlorides, acids, and extreme temperatures. Outperforms 304 in harsh environments.
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Pozidriv (Pozidrive) drive – Distinct from Phillips, the extra cross‑recesses provide greater torque transfer and significantly reduce cam‑out. Your driver stays engaged, even under load.
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Countersunk flat head (90°, DIN 965) – Sits flush in tapered holes for a smooth, tamper‑resistant finish. Ideal for space‑constrained assemblies.
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Full thread design – Threads run the entire shank length for secure fastening in delicate or lightweight materials. M2 and M2.5 coarse pitches (0.4mm and 0.45mm).
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Ultra‑thin profile – Minimizes protrusion in confined assemblies. Perfect for micro‑engineering and precision devices.
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High‑precision threads – Engineered for seamless compatibility with delicate components like plastics or thin metals.
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Marine‑grade durability – Withstands saltwater, humidity, and harsh chemicals – ideal for submersible or corrosive environments.
📏 Technical Specifications – M2 & M2.5 Pozidriv Countersunk Screws (A4 Stainless, DIN 965)
| Specification |
M2 |
M2.5 |
| Thread Diameter (d) |
2mm |
2.5mm |
| Thread Pitch (p) |
0.4mm |
0.45mm |
| Head Style |
Countersunk flat head (90°, DIN 965) |
| Drive Style |
Pozidriv (Pozi) – use PZ0 or PZ1 bit |
| Material |
A4 Stainless Steel (316 / marine grade) |
| Thread Type |
Fully threaded |
| Length Measurement |
Length includes head (total screw length – DIN 965 standard) |
📌 Key Applications
| Industry |
Specific Uses |
| Micro‑Engineering |
Robotics, drones, precision instruments, miniature mechanical assemblies |
| Medical Devices |
Surgical tools, diagnostic equipment, implantable device housings |
| Marine Electronics |
Underwater sensors, boat electronics, coastal infrastructure, submersible equipment |
| Consumer Electronics |
Smartphones, wearables, circuit board mounts, compact device assemblies |
| Optics & Photonics |
Lens mounts, laser components, optical alignment fixtures |
| Aerospace |
Lightweight panels, avionics, satellite systems, high‑vibration assemblies |
❓ FAQs – A4 Stainless Pozidriv Countersunk Screws
🔸 What is the difference between Pozidriv and Phillips drive?
Pozidriv has additional smaller cross‑recesses at 45° angles and a blunter tip. A Phillips driver will fit loosely and will cam‑out or damage the recess. Always use a genuine Pozidriv (Pozi) driver bit – for M2 and M2.5, use PZ0 or PZ1. Using the correct bit gives you much better torque without slipping.
🔸 How is length measured for countersunk screws? Are these fully threaded?
For DIN 965 countersunk screws, length is measured as total screw length including the head – from the top of the flat head to the tip. Yes – they are fully threaded (threads run the entire shank length).
🔸 Will A4 (316) stainless steel rust in saltwater?
A4 (316) stainless is highly resistant to saltwater corrosion and is the go‑to choice for marine and coastal 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 is the advantage of the countersunk head design?
The 90° countersunk head sits flush with the surface when installed in a tapered hole. This provides a smooth, snag‑free finish, minimizes protrusion in tight spaces, and offers a tamper‑resistant appearance – ideal for security‑sensitive applications.
🔸 Can I use these screws with nuts, or are they self‑tapping?
These are standard machine screws – they require a matching metric nut (M2 or M2.5) or a pre‑tapped hole. They are not self‑tapping. For best corrosion resistance, pair them with A4 stainless nuts.
🔸 What lengths are available for M2 and M2.5?
We offer various lengths – please select from the dropdown options. Typical lengths range from 3mm to 20mm depending on the diameter. If you need a specific length not listed, contact us.
