Knurled Thumb Screws Aluminum Alloy — M2 M2.5 M4 M5 M6 Flat Head Hand Grip Knob Bolts

Match the thread diameter to your tapped hole (e.g., M4 for an M4 threaded insert). For length, the screw should engage at least 1.5× the thread diameter into the material — for example, an M4 screw typically needs at least 6mm of thread engagement. When in doubt, choose a longer option and use a washer to adjust. Inch-to-metric conversion reference: 4mm ≈ 5/32", 8mm ≈ 5/16", 12mm ≈ 15/32", 15mm ≈ 19/32", 20mm ≈ 25/32", 25mm ≈ 1".

Aluminum alloy thumb screws are generally suitable for light-to-medium clamping loads in electronics, RC vehicles, camera rigs, and panel assemblies. They are not intended for high-torque structural applications. For heavy-duty use, stainless steel thumb screws are typically recommended.

Aluminum alloy has natural corrosion resistance and generally performs well in dry or mildly humid outdoor environments. However, for prolonged exposure to rain, salt spray, or harsh chemicals, an anodized or stainless steel fastener is typically a better choice. Contact us to confirm suitability for your specific outdoor application.

These thumb screws use standard ISO metric threads (M2, M2.5, M4, M5, M6). They are compatible with any metric-threaded hole or insert of the matching size. They are not compatible with UNC/UNF inch-standard threads. If your project uses SAE fasteners, please verify compatibility before ordering.

No tools are required. The knurled flat head is designed for finger-tightening by hand. This makes them ideal for panels, enclosures, and assemblies that need frequent access or adjustment — a key reason makers choose knurled thumb screws over standard hex bolts for quick-release applications.

Color is primarily aesthetic. All 10 color options (Dark Red, Rose Red, Golden, Royal Blue, Sky Blue, Black, Silver, Green, Purple, Orange) are made from the same aluminum alloy material. Choose a color that matches your build's theme, or use contrasting colors for easy identification of different fastener positions — a common practice in RC car body panel screw setups and modular electronics enclosures.

Yes. These knurled thumb screws are commonly used with plastic enclosures, RC car bodies, drone frames, and electronics housings. They work best with metal threaded inserts or brass heat-set inserts in plastic. Directly threading into soft plastic is generally not recommended for repeated use, as it may strip the threads over time.