Knurled Thumb Screws UNC 6#-32 — Aluminum Hand-Grip Knob Bolts, 10 Colors

Measure the total thickness of the material you need to clamp or fasten, then add 2–3 thread engagements for a secure hold. This product is available in 10mm (≈3/8"), 16mm (≈5/8"), and 20mm (≈13/16"). As a general rule, thread engagement should be at least 1× the screw diameter — for a #6-32 screw, that is typically 3–4mm minimum. When in doubt, size up to the next length.

These thumb screws are made from aluminum alloy with an anodized finish. Anodizing generally improves surface hardness and corrosion resistance compared to bare aluminum, while keeping the screws lightweight — a useful combination for electronics enclosures, RC builds, and portable DIY projects.

The anodized aluminum finish provides moderate corrosion resistance, making these screws generally suitable for light outdoor or humid-environment use. For prolonged saltwater exposure or heavy-weather conditions, a stainless steel alternative is typically recommended. For most indoor and sheltered outdoor applications, these should perform well.

These use the UNC (Unified National Coarse) 6#-32 thread standard, which is one of the most common thread standards in the United States. They are compatible with any standard UNC 6#-32 nut, threaded insert, or tapped hole. Always verify your mating thread specification before ordering.

As aluminum thumb screws designed for hand-tightening, these are generally suited for light-duty clamping and panel fastening rather than high-torque structural applications. Typical hand-tightening torque for a #6-32 aluminum screw is in the range of 2–5 in-lbs. For higher load requirements, a steel fastener is recommended.

The colors are achieved through anodizing, which is an electrochemical process that integrates into the aluminum surface rather than sitting on top like paint. This means the color finish generally does not chip or peel under normal use and does not significantly affect the screw's mechanical performance. Color-coding can also be useful for organizing or identifying different fastener positions in a build.

Yes. The knurled head design is specifically intended for tool-free, hand-tightening. The Ø8mm × H6mm knurled knob provides enough grip surface for finger-tightening in most panel and enclosure applications. If you need a tighter hold than hand-tightening allows, these screws may not be the right choice for that application.

All pack sizes contain the same screw — the only difference is quantity. The 1 PCS option is useful for testing fit before committing to a larger order. The 5, 10, and 20 PCS packs offer a lower per-unit cost and are practical for builds that require multiple fasteners or for keeping spares on hand.