M5 M6 M8 Plastic Black Rosette Thumb Screws Knobs Bolt Star Knob Thumbscrews

Match the thread diameter to your existing tapped hole or nut. M5 (5mm shank) suits lighter panels and smaller enclosures; M6 (6mm) is the most common general-purpose metric size for equipment covers and jigs; M8×80mm is suited to thicker assemblies requiring a longer reach. If you are unsure, measure the inner diameter of your threaded hole — it should match the nominal thread size.

As a general rule, select a length that provides at least 1× the thread diameter of engagement beyond the panel. For example, for a 10mm thick panel with an M6 screw, a 16mm or 20mm length gives adequate thread engagement. Add panel thickness + nut height (if using a nut) + desired engagement depth to determine the minimum length needed.

The plastic knob head is inherently moisture-resistant. The steel shank provides standard corrosion resistance suitable for indoor and sheltered applications. For prolonged outdoor exposure or high-humidity environments, consider applying a thread sealant or corrosion inhibitor to the shank, or contact us to confirm suitability for your specific conditions.

Yes. The steel shank uses standard ISO metric threads (M5, M6, or M8), so these thumb screws are compatible with any standard metric hex nut, wing nut, threaded insert, or tapped hole of the matching size and pitch. No special hardware is required.

These are designed for hand-tightening applications — not high-torque fastening. The six-petal rosette geometry allows firm finger pressure for secure clamping of panels and covers, but they are not intended to replace tool-tightened fasteners in structural or high-vibration joints. For applications requiring specific torque values, contact us to confirm suitability.

The grade number refers to the knob outer diameter classification used in the product family. 25# knobs (used on M5 and M6 variants) have a smaller diameter head, while 38# knobs (used on the M8×80mm variant) have a larger diameter head that provides more leverage for hand tightening on heavier assemblies. Select based on the thread size you need — the grade is matched to the thread in each variant option.

Yes — these are a common choice for exactly those applications. The tool-free rosette knob is well-suited to access panels on electronics enclosures, side covers on CNC router frames, and removable panels on 3D printer enclosures where frequent access is needed. Verify the thread size matches your frame's tapped holes or T-nuts before ordering.