316 Stainless Steel Countersunk Phillips Machine Screws — Reliable Flat Head Fasteners for Demanding Environments
When a standard screw just won't hold up — whether you're working near saltwater, in a humid workshop, or on a precision electronics project — you need a fastener built for the long haul. These M5 and M6 countersunk Phillips machine screws are engineered for builders, makers, and professionals who refuse to compromise on corrosion resistance.
Machined from A4-grade 316 stainless steel, each screw features a flat countersunk head with a Phillips drive, metric coarse threading, and a fully threaded shank. Available in M5 and M6 diameters with lengths ranging from 8 mm to 100 mm (approximately 0.31 in to 3.94 in), and in pack sizes from 5 to 200 pieces to match your project scale.
Whether you're assembling marine hardware, mounting electronics panels, building outdoor furniture, or tackling a precision DIY repair, these screws deliver a flush, clean finish with the strength and longevity that 316 stainless is known for. Fully threaded for maximum grip — no partial-thread guesswork.
🔩 Compatible with standard metric coarse-thread nuts and tapped holes — M5 (0.8 mm pitch) and M6 (1.0 mm pitch).
✅ Key Features of These 316 Stainless Countersunk Phillips Machine Screws
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🛡️ A4 / 316 Stainless Steel — Molybdenum-enhanced alloy for superior resistance to corrosion, pitting, and chloride environments, including marine and coastal use
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🔩 Fully Threaded Shank — Thread runs the full length for maximum clamping force and versatility across material thicknesses
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📐 Flat Countersunk Head — Sits flush with the surface for a clean, professional finish in wood, metal, and composite materials
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⚙️ Phillips Drive — Compatible with standard #2 Phillips screwdrivers and power bits for fast, reliable installation
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📏 Metric Coarse Thread — M5 × 0.8 mm and M6 × 1.0 mm pitch; length measurement includes the head per flat-head fastener standard
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📦 Flexible Pack Sizes — Order 5, 10, 30, 50, 100, or 200 pieces to match your exact project needs without overstocking
📐 Technical Specifications — 316 Stainless Countersunk Phillips Machine Screws
| Material |
316 Stainless Steel (A4 Grade) |
| Head Style |
Flat Countersunk |
| Drive Type |
Phillips (Cross) |
| Thread Standard |
Metric Coarse |
| Available Diameters |
M5, M6 |
| M5 Thread Pitch |
0.8 mm |
| M6 Thread Pitch |
1.0 mm |
| Available Lengths |
8 mm – 100 mm (length includes head) |
| Thread Coverage |
Fully threaded |
| Finish |
Plain (natural stainless) |
| Pack Sizes |
5 / 10 / 30 / 50 / 100 / 200 pcs |
| Corrosion Resistance |
Excellent — suitable for marine and chemical environments |
❓ Frequently Asked Questions
What sizes are available?
These screws are available in M5 and M6 thread diameters, with lengths typically ranging from 8 mm to 100 mm. Select your preferred size and quantity combination from the variant options above.
Are these screws fully threaded?
Yes — all screws in this listing are fully threaded from tip to head, providing maximum engagement and clamping force regardless of material thickness.
What is 316 stainless steel, and why does it matter?
316 stainless steel (A4 grade) contains added molybdenum, giving it superior corrosion and pitting resistance compared to 304 (A2). It is particularly suitable for marine, coastal, and chemical environments where standard stainless would eventually corrode.
steel steel steel Does the screw length include the head?
Yes. Per the standard for countersunk (flat head) fasteners, the listed length includes the head. This is different from pan-head or hex-head screws where length is measured under the head.
What thread pitch do these screws use?
These screws use metric coarse threads. M5 screws generally have a 0.8 mm pitch and M6 screws typically have a 1.0 mm pitch. They are compatible with standard metric coarse nuts and tapped holes.
What are typical applications for these screws?
These flat-head machine screws are commonly used in electronics repair, marine hardware, furniture assembly, outdoor structures, DIY projects, and any application requiring a flush-mount fastener with strong corrosion resistance.
Can I order a quantity larger than what is shown in stock?
If you need more than the listed inventory, please contact our customer service team and we will do our best to accommodate your bulk order request.
🛒 Select your Screw Size and QTY above, then add to cart — ships from our US warehouse.
