🔘 Aluminium Knurled Thumb Screws – Flat Head Hand Grip Bolts, 6#-32 UNC or M2.5 Metric (Anodised Finish)
You’re working on a small machine, a precision mould, or a bearing assembly – and you need a thumbscrew that’s comfortable to turn by hand, won’t rust, and looks clean. These flat head knurled thumb screws are machined from 6061 aluminium with a durable anodised finish. Choose either 6#-32 UNC (10mm thread length) or M2.5 x 8mm metric. The diamond knurled head gives you a secure, non‑slip grip – no tools needed. Fully threaded for maximum holding power. Lightweight, corrosion‑resistant, and available in multiple colours. Perfect for tool‑less fastening on jigs, fixtures, and industrial equipment.
✨ Key Features – Aluminium Flat Knurled Thumb Screws
- 🔘 Flat knurled head – Low‑profile design with diamond knurling for a secure, comfortable fingertip grip.
- 🎨 Anodised aluminium 6061 – Lightweight, corrosion‑resistant, and available in a range of colours (contact us for options).
- 📏 Two thread options – 6#-32 UNC x 10mm (imperial) or M2.5 x 8mm (metric). Choose the one that fits your equipment.
- 🛡️ Fully threaded stud – Thread runs the entire length under the head for maximum grip in tapped holes or with nuts.
- ✨ Smooth, burr‑free finish – High quality workmanship, even threads, uniform force – no slipping or stripping.
- 🔧 Widely used – Machinery, precision moulds, bearing assembly, jigs, fixtures, and industrial equipment.
📏 Specifications – Flat Knurled Thumb Screws (Aluminium)
| Thread Option |
Thread Size |
Thread Pitch |
Thread Length (mm, under head) |
Head Style |
Head Diameter (approx.) |
Head Height (approx.) |
Material / Finish |
| Imperial |
6#-32 UNC |
32 TPI |
10 mm |
Flat knurled |
~8‑10 mm |
~4‑5 mm |
6061 aluminium / Anodised |
| Metric |
M2.5 |
0.45 mm |
8 mm |
* Length measured from underside of head to tip. Fully threaded. Tolerance ±0.3 mm. Colour may vary slightly due to photography and lighting.
🛠️ Where to Use These Thumb Screws
| Application |
Typical Use |
| Machinery & equipment |
Tool‑less adjustment clamps, access panels, fixture stops |
| Precision moulds |
Quick‑release fasteners, alignment pins, handle knobs |
| Bearing assembly & jigs |
Adjustable stops, workholding clamps, assembly fixtures |
| DIY & hobby |
3D printer bed leveling, camera rigs, model making |
❓ Frequently Asked Questions – Aluminium Knurled Thumb Screws
1. How do I choose between 6#-32 and M2.5?
Check the threaded hole on your equipment. If it uses an imperial #6-32 UNC thread (common in older US machinery and some PC cases), choose the 6#-32 option. If it uses a metric M2.5 thread (common in European/Asian equipment and small electronics), choose the M2.5 option. They are not interchangeable.
2. Are these screws fully threaded? Can I use them with a nut?
Yes – both versions are fully threaded from under the head to the tip. For plain holes, use a matching #6-32 UNC or M2.5 metric nut. For pre‑tapped holes, no nut is needed.
3. Will the anodised finish wear off? What colours are available?
Anodising is a hard, electrochemical finish that bonds to the aluminium – it resists scratches and fading far better than paint. Standard colour is natural silver. Other colours (black, red, blue, gold, green, etc.) are available on request – contact us for custom anodising.
4. Can I use these screws outdoors? Will they rust?
Aluminium naturally forms a protective oxide layer, and anodising adds extra corrosion resistance. They are suitable for indoor and light outdoor use. For continuous saltwater or harsh chemical environments, we recommend stainless steel thumb screws.
5. How do I measure the length of a flat knurled thumb screw?
The length is measured from the underside of the head (where the knurling meets the shaft) to the tip of the threaded stud. The head itself is NOT included. For example, the 6#-32 version has a 10mm thread length under the head.
6. Can I get other lengths or custom colours?
Yes – we offer custom lengths and anodised colours. Please contact us with your requirements.
