5pc M4 Adjustable Knurled Thumb Shoulder Screws 5-100mm Stainless Steel+Aluminum

Measure the total thickness of the material stack you need to clamp or pass through, then add 2–4 mm for thread engagement in the receiving nut or tapped hole. For example, if your panel is 8 mm thick and you need 3 mm of thread engagement, select the 12 mm length. The 5–100 mm range covers most panel, jig, and fixture scenarios.

These screws are designed for hand-tightened, adjustable fastening applications such as jigs, fixtures, enclosures, and 3D printer frames — not for high-torque structural joints. The stainless steel shank provides solid mechanical strength for repeated adjustment cycles, but they should not replace torqued hex bolts in load-bearing structural assemblies.

Anodized aluminum forms a hard oxide layer that resists light corrosion, UV exposure, and surface abrasion better than bare aluminum. In typical indoor workshop or electronics environments, the finish remains stable with normal use. Prolonged exposure to salt spray or strong acids may degrade the anodizing over time.

Yes. The threaded shank follows the ISO metric M4 standard with a 0.7 mm pitch, making it compatible with any standard M4 nut, M4 tapped hole, or M4 threaded insert. No special tooling or adapters are required.

Color selection is typically functional rather than purely aesthetic. Common approaches include using one color per assembly zone (e.g., blue for electrical panels, red for mechanical stops), using a single color for all thumb screws to distinguish them from standard fasteners, or matching your enclosure or frame color for a clean visual finish. All 10 colors share the same dimensions and thread specification.

The stainless steel shank offers good corrosion resistance for light outdoor and humid indoor use. The anodized aluminum head also resists moisture better than bare aluminum. For prolonged outdoor exposure or marine environments, consider applying a light coating of anti-seize compound to the threads to prevent galvanic corrosion between the stainless steel and aluminum components.

A standard thumb screw is threaded along its full length. A thumb shoulder screw has an unthreaded cylindrical shoulder section between the head and the threaded tip. The shoulder acts as a precise locating or pivot surface, useful in jigs and fixtures where the screw must align components as well as clamp them. These screws combine both features: a knurled thumb head for hand operation and a shoulder for positional accuracy.