🔩 M3–M6 Stainless Steel Countersunk Torx Screws – A2 Machine Screws, Fully Threaded (4–50mm Overall Length)
You’re mounting a machine guard, securing an outdoor electronic enclosure, or assembling a piece of marine equipment – and you need a flush‑finish screw that won’t strip or rust. These M3 to M6 countersunk screws feature a Torx (star) drive, which completely eliminates cam‑out, even under high torque. Made from A2 stainless steel (304), they resist corrosion in humid, coastal, and industrial environments. The 90° flat head sinks perfectly into a pre‑drilled countersink, leaving a smooth, snag‑free finish. Available in M3, M4, M5, and M6 diameters, with overall lengths from 4mm to 50mm (including the head). Fully threaded. Ideal for machinery, automotive trim, marine hardware, and outdoor furniture.
✨ Key Features – Countersunk Torx Machine Screws (A2 Stainless)
- ⭐ Torx (six‑lobe) drive – No cam‑out, allows high torque with power tools. Reduces wear on bits and screw recesses.
- 🔽 Countersunk flat head (90°) – Sits flush with the surface after proper countersinking. Smooth, professional finish.
- 🛡️ A2 stainless steel (304) – Excellent corrosion resistance, oxidation resistance, and heat resistance. High strength and toughness.
- 📏 Metric sizes M3, M4, M5, M6 – Popular diameters for light to medium duty fastening.
- 📐 Overall lengths 4–50mm (including head) – Example: M4 x 10mm means total length from top of head to tip is 10mm. Fully threaded.
- ⚙️ DIN 965 compatible dimensions – Precision head geometry with 90° countersink angle. Torx bit sizes: M3→T10, M4→T20, M5→T25, M6→T30.
- 🔧 Widely used – Machinery, electronic enclosures, automotive trim, marine hardware, outdoor furniture, and general construction.
📏 Specifications – M3 to M6 Countersunk Torx Screws (A2 Stainless)
| Thread Diameter (M) |
Thread Pitch (mm) |
Head Diameter (dk) – mm |
Head Height (k) – mm |
Torx Bit Size |
Overall Length Range (mm) * |
| 📐 Length measured from top of head to tip (total screw length). Fully threaded. Select exact size from dropdown. |
| M3 |
0.5 |
5.5 |
1.9 |
T10 |
4, 5, 6, 8, 10, 12, 16, 20, 25, 30, 35, 40, 45, 50
(exact availability varies) |
| M4 |
0.7 |
8.2 |
2.5 |
T20 |
| M5 |
0.8 |
9.1 |
2.8 |
T25 |
| M6 |
1.0 |
10.8 |
3.2 |
T30 |
* Lengths are typical – exact availability may vary. Please allow minor manual measurement errors. 100% brand new, high quality.
📋 Why Choose Torx Drive for Countersunk Screws?
| Advantage |
Description |
| No cam‑out |
Torx geometry keeps the bit fully engaged, even under high torque – no slipping or stripping. |
| Higher torque capacity |
Ideal for power tools and applications where you need to tighten firmly without damaging the recess. |
| Even force distribution |
The six lobes spread stress evenly, reducing wear on both the driver bit and the screw recess. |
| Flush finish |
Countersunk head sits flush – perfect for smooth surfaces and snag‑free assemblies. |
❓ Frequently Asked Questions – Countersunk Torx Screws
1. How do I measure the length of a countersunk Torx screw?
For countersunk screws, the length is measured overall – from the top of the head to the tip. So an “M4 x 10mm” screw has a total length of 10mm including the head. This matches our listing.
2. Do I need to countersink the hole for these screws to sit flush?
Yes – these are true 90° countersunk screws. To achieve a flush finish, drill a matching 90° countersink hole. Use a countersink bit slightly larger than the head diameter.
3. Are these screws fully threaded? What about longer lengths like 50mm?
Yes – all M3–M6 screws in this range (up to 50mm) are fully threaded from under the head to the tip, giving you maximum grip in blind holes or through‑nut applications.
4. Can I use these screws outdoors? Will they rust?
A2 stainless steel (304) is highly corrosion‑resistant and suitable for outdoor use in most environments – rain, humidity, and coastal areas. For continuous saltwater immersion, consider A4 (316) stainless, but for most general outdoor applications, A2 is excellent and will not rust.
5. What Torx bit size do I need for M3, M4, M5, M6?
M3 → T10, M4 → T20, M5 → T25, M6 → T30. Always use a quality Torx bit that fits snugly to avoid stripping the recess.
6. Can I use these screws with a nut? What size nut fits?
Yes – these are machine screws. Use standard metric nuts of the same thread size (e.g., M4 nut for M4 screw). For outdoor use, pair with stainless steel nuts.
