🔩 M5–M10 Black Cap Head Socket Screws – Torx Drive, Hex Socket Style, Carbon Steel (6–40mm Lengths)
You’re bolting down a machine guard, mounting a heavy bracket, or assembling industrial equipment – and you need screws that look sharp, drive securely, and won’t strip. These black cap head screws feature a Torx (star) drive combined with a classic hex socket cap profile. The Torx recess eliminates cam‑out, letting you apply high torque with confidence. The black finish provides a professional, matte appearance while adding a layer of corrosion resistance. Available in M5, M6, M8, and M10 diameters with lengths from 6mm to 40mm (measured from under the head). Made from carbon steel, they offer excellent strength for demanding applications. Whether you’re customizing a motorcycle, building a 3D printer, or repairing industrial machinery, these screws deliver reliable, repeatable tightening every time.
✨ Key Features – Black Cap Head Torx Screws (Hex Socket Style)
- 🔘 Cap head design (socket head) – High cylindrical profile with a large internal drive. Provides maximum torque transmission and a clean, industrial look.
- ⭐ Torx (star) drive – Virtually eliminates cam‑out. The star shape distributes force evenly, reducing wear on the driver bit and the screw recess.
- ⚫ Black finish – Matte black coating adds corrosion resistance and a professional, low‑glare appearance. Great for custom builds and visible assemblies.
- 📏 Metric sizes M5, M6, M8, M10 – Four popular diameters for light to heavy‑duty fastening. Covers everything from machinery to automotive.
- 📐 Lengths from 6mm to 40mm (under head) – Choose exactly what you need for your panel thickness. Fully threaded for most lengths; longer M8/M10 may have partial threads.
- 💪 Carbon steel construction – High strength, durable, and impact resistant. Black finish helps protect against rust in indoor and light outdoor use.
- 💰 High quality, great value – 100% brand new, inexpensive but reliable – ideal for workshops, maintenance, and DIY projects.
📏 Available Sizes – Black Cap Head Torx Screws (Metric)
| Thread Diameter |
Length (mm, under head) * |
Thread Pitch (mm) |
Head Style |
Drive |
Material / Finish |
| 📐 Length measured from under the head (grip length). Select exact size from dropdown. |
| M5 |
6, 8, 10, 12, 16, 20, 25, 30, 35, 40 |
0.8 |
Cap head (socket head)
|
Torx (star)
|
Carbon steel / Black finish
|
| M6 |
8, 10, 12, 16, 20, 25, 30, 35, 40 |
1.0 |
| M8 |
10, 12, 16, 20, 25, 30, 35, 40 |
1.25 |
| M10 |
12, 16, 20, 25, 30, 35, 40 |
1.5 |
* Length = threaded portion under the head. Most lengths up to 25mm are fully threaded; longer may have partial thread. Please allow minor manual measurement errors.
📋 Drive & Head Details – Torx vs. Hex Socket
| Feature |
Description |
| Drive style |
Torx (star) – e.g., T20 for M5/M6, T25 for M8, T30 for M10 (approx.). Always check fit with a Torx bit. |
| Head profile |
Cylindrical cap head – similar to standard socket cap screws. High profile allows deep drive engagement. |
| Black finish |
Black oxide or black coated – adds mild corrosion protection and a matte appearance. Not as durable as stainless, but fine for indoor or light outdoor use. |
| Typical applications |
Machine assembly, automotive parts, 3D printer frames, industrial equipment, motorcycle accessories, and DIY metalwork. |
❓ Frequently Asked Questions – Black Cap Head Torx Screws
1. Are these screws Torx or hex socket (Allen)? The title says both.
These screws have a Torx (star) drive – not hex socket. The title includes “Allen” for search visibility, but the actual drive is Torx. Torx provides superior torque transfer and eliminates cam‑out. Use a standard Torx bit (e.g., T20, T25, T30) to drive them. We recommend using the correct Torx bit for best results.
2. How do I measure the length of a cap head screw?
For cap head screws (socket head cap screws), the length is measured from the underside of the head (the flat bearing surface) to the tip. The head height is NOT included. So an “M6 x 20mm” screw has a 20mm long threaded shaft (or partially threaded shank) under the head. This matches the lengths shown in our table.
3. Are these screws fully threaded?
For lengths up to about 25mm (depending on diameter), they are typically fully threaded. Longer screws (e.g., M8 x 40mm) may have a partial thread – meaning an unthreaded shank near the head. This is standard for socket cap screws. If you need full thread for a specific length, please contact us.
4. Will the black finish rust? Can I use these screws outdoors?
The black finish provides moderate corrosion resistance, but carbon steel will eventually rust if exposed to moisture over time. These screws are best for indoor use or dry environments. For outdoor or marine use, we recommend stainless steel. However, for garage projects, machine tools, or indoor furniture, the black finish will last a long time with minimal care.
5. What Torx bit size do I need for each screw?
Typical matching: M5 uses T20, M6 uses T20 or T25, M8 uses T25 or T30, M10 uses T30 or T40. These can vary by manufacturer. Always use a Torx bit that fits snugly without wobbling to avoid stripping the recess.
6. Can I use a hex (Allen) key on these screws?
No – these are Torx drive, not hex socket. Using a hex key will damage the recess. You need a Torx star bit. If you prefer hex drive, please see our other listings for standard Allen socket cap screws.
