🔩 M5 & M6 Knurled Thumb Screws – 303 Stainless Steel Hand Grip Knob Bolts (10–25mm Thread Lengths)
You’re tired of reaching for a screwdriver every time you need to adjust a jig, a camera rig, or a piece of shop equipment. These M5 and M6 knurled thumb screws let you fasten and release by hand – no tools required. The diamond‑knurled stainless steel head gives you a secure, non‑slip grip, even with oily fingers. Made from 303 stainless steel, they resist rust and corrosion, so they’ll look good and work well for years. Choose thread lengths from 10mm to 25mm (under head). Fully threaded for maximum holding power. Ideal for 3D printer bed leveling, machine access panels, camera brackets, and any application where you want quick, tool‑less adjustments.
✨ Key Features – 303 Stainless Steel Knurled Thumb Screws
- 🔘 Knurled cylinder head – Diamond knurling provides excellent fingertip grip for hand tightening and loosening.
- 🛡️ 303 stainless steel – Offers good corrosion resistance, high strength, and a clean, professional appearance. Won’t rust like carbon steel.
- 📐
Tool‑less operation – No screwdrivers, hex keys, or wrenches needed. Perfect for frequent adjustments.
- 📏 M5 and M6 metric threads – Popular sizes for machinery, 3D printers, camera gear, and general DIY.
- 📐 Thread lengths 10, 12, 14, 16, 20, 25mm (under head) – Fully threaded for maximum grip in tapped holes or with nuts.
- 📊 Consistent head dimensions – Head diameter 14mm, head height 8mm. Comfortable and easy to grip.
- 🔧 Widely used – 3D printer bed leveling, machine guards, camera bracket locks, electronic enclosures, and workshop jigs.
📏 Specifications – M5 & M6 Stainless Steel Knurled Thumb Screws
| Thread Diameter (M) |
Thread Pitch (mm) |
Thread Length (mm, under head) * |
Head Diameter (mm) |
Head Height (mm) |
Material |
| M5 |
0.8 |
10 |
14 ±0.1 |
8.0 ±0.1 |
303 Stainless Steel |
| 12 |
| 14 |
| 16 |
| 20 |
| 25 |
| M6 |
1.0 |
10 |
| 12 |
| 14 |
| 16 |
| 20 |
| 25 |
* Thread length measured from underside of head to tip. Fully threaded. Select exact size from dropdown. Head dimensions are nominal – please allow minor tolerances.
🛠️ Typical Applications for M5 / M6 Thumb Screws
| Application |
Typical Use |
| 3D printers |
Bed leveling knobs, filament guide clamps, enclosure thumb screws |
| Camera & video rigs |
Tripod plate locks, bracket clamps, quick‑release knobs |
| Machine tools & fixtures |
Fence stops, jig clamps, tool‑less adjustment handles |
| Electronics enclosures |
Access panel thumbscrews, battery compartment covers |
| Workshop & DIY |
Custom jigs, workbench stops, quick‑release hardware |
❓ Frequently Asked Questions – Stainless Steel Thumb Screws
1. How do I measure the length of a thumb screw?
For these thumb screws, the length is measured from the underside of the head (where the knurling ends) to the tip of the threaded shaft. The head itself is NOT included. So an “M5 x 16mm” screw has a 16mm long threaded shaft under the head. All our lengths follow this standard.
2. Are these screws fully threaded? What about the longer 25mm version?
Yes – all M5 and M6 screws in this range (10mm to 25mm) are fully threaded from under the head to the tip, giving you maximum grip in blind holes or when using a nut.
3. Will 303 stainless steel rust? Can I use these outdoors?
303 stainless offers good corrosion resistance, similar to 304. It is suitable for indoor use and light outdoor exposure. For continuous saltwater or harsh chemical environments, consider 316 stainless. For most workshops, camera gear, and indoor machinery, 303 will not rust.
4. Do I need a nut or washer with these thumb screws?
If your equipment has a tapped hole (e.g., a 3D printer bed with an M5 threaded insert), no nut is needed. If you are fastening through a plain hole, use a standard metric nut of the same thread size (M5 or M6). Washers are optional for load distribution.
5. What is the head diameter? Is it comfortable to grip?
The head diameter is 14mm with a height of 8mm – a comfortable size for adult fingers. The diamond knurling pattern ensures a secure grip, even when turning against resistance.
6. Can I get other thread lengths or custom sizes?
We offer the sizes listed (10–25mm). For other lengths (e.g., 30mm, 40mm) or different thread diameters (M3, M4, M8, etc.), please contact us – custom orders are available.
