🔩 A2 Stainless Steel Countersunk Socket Screws – Allen Key Flat Head Bolts M3 to M8 | DIN7991
🏷️ Brand: HomeDIYer Fastener | DIN7991 | A2-70 | Fully Threaded | Hex Bits Included
📌 Overview — Flush-fit fastening with high torque capability. When you need a completely smooth surface with no protruding heads, our A2 Stainless Steel Countersunk Socket Screws (DIN7991) are the answer. The 90° flat head sits flush with or below the workpiece surface when used in a countersunk hole, providing a clean, snag-free finish. The hex socket drive (Allen key) allows high torque without cam-out, while the A2-70 stainless steel construction resists rust and corrosion – ideal for marine hardware, decking, machinery guards, furniture, and any application where a smooth surface is critical. Fully threaded from M3 to M8, these screws are measured overall (including the head). We include the correct hex screwdriver bits with your order. Choose your exact length and quantity – perfect for builders, woodworkers, and industrial assemblers.
✨ Key Features of Countersunk Socket Screws (DIN7991)
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Countersunk 90° Flat Head – Sits flush with or below the surface when installed in a countersunk hole – no snagging, no protruding heads.
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Hex Socket Drive (Allen Key) – Enables high torque transfer without cam-out; hex bits included with your order (2mm to 5mm).
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A2-70 Stainless Steel (304 equivalent) – Excellent corrosion resistance for outdoor, marine, and industrial environments.
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Fully Threaded (DIN7991) – Threads run the entire length for maximum grip; length is measured overall (includes head).
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Metric Coarse Threads M3–M8 – Standard pitches: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M8x1.25.
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Untreated Natural Stainless Finish – Clean, smooth surface with no coatings to chip or peel – professional appearance.
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Versatile Length Options – Order any overall length you need, from short (6mm) to longer (50mm+), fully threaded throughout.
📏 Technical Specifications – Countersunk Socket Screws (DIN7991, Metric Coarse)
| Thread Size |
Thread Pitch (mm) |
Allen Key Size (mm) |
Head Diameter (mm) |
Head Height (mm) |
| M3 |
0.5 |
2.0 |
6.0 |
2.5 |
| M4 |
0.7 |
2.5 |
8.0 |
2.6 |
| M5 |
0.8 |
3.0 |
10.0 |
4.1 |
| M6 |
1.0 |
4.0 |
12.0 |
4.9 |
| M8 |
1.25 |
5.0 |
16.0 |
6.2 |
💡 Length & ordering info: Screws are fully threaded. Length is measured overall (including the head) – this is standard for countersunk screws. Choose your preferred overall length (e.g., 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm) — sold as per your requirement. Hex bits are included with your order – one bit per size or a multi-bit driver, depending on the pack.
🔧 Installation tip: For a perfect flush fit, pre-drill a countersunk hole with a 90° countersink bit. The head diameter and angle are standard (90°). These screws are not self-countersinking – proper preparation ensures a professional finish.
❓ Frequently Asked Questions – Countersunk Allen Socket Screws
How is the length measured for countersunk screws?
📏 For DIN7991 countersunk socket screws, the length is measured overall – from the top of the head to the tip. This is different from hex head or button head screws (which measure under the head). Always verify your required length based on the overall measurement.
Do I need to countersink the hole before using these screws?
🔧 Yes. For the head to sit flush with the surface, you must pre-drill a 90° countersink. These screws are not self-countersinking. Proper countersinking ensures a professional finish and prevents material cracking (especially in wood or plastic).
Are these screws fully threaded? What lengths are available?
✅ Yes, all sizes are fully threaded per DIN7991. Overall lengths from 6mm up to 50mm (common: 6,8,10,12,16,20,25,30,35,40,45,50mm). Custom lengths available for bulk orders – contact us.
What hex key/bit do I need? Do you include them?
🔩 M3 → 2mm, M4 → 2.5mm, M5 → 3mm, M6 → 4mm, M8 → 5mm. Yes, the box includes the correct hex screwdriver bits for the screws you order – no need to buy tools separately.
Are these screws corrosion-resistant for outdoor use?
🌊 Yes – A2-70 stainless steel (304 grade) provides excellent corrosion resistance for outdoor furniture, marine hardware, decking, and coastal environments. They will not rust like carbon steel. For continuous saltwater immersion, consider A4 (316) stainless.
⚙️ HomeDIYer Fastener — Precision stainless steel countersunk screws for flush-mount applications. Order your exact size, length, and quantity today.
