Aluminum +Stainless Steel Knurled Thumb Screws 6#-32 M3 M3.5 M4 Bolts Rose Red

Match the thread diameter to your existing tapped hole or threaded insert. UNC 6#-32 is a standard imperial thread used in electronics enclosures and rack equipment in North America. M3, M3.5, and M4 are metric threads common in European and Asian-standard hardware, 3D printer frames, and aluminum extrusion systems. Measure your hole with a thread gauge or check your equipment's documentation before ordering — metric and UNC threads are not interchangeable.

Thread length should be at least 1.5× the thread diameter for adequate engagement in metal, or at least 2× in softer materials like plastic or thin aluminum sheet. For example, an M4 screw threading into a 2 mm aluminum panel should have at least 6–8 mm of thread engagement. If you are threading into a nut or threaded insert, match the length to the insert depth plus any clearance needed.

These thumb screws are designed for panel fastening, access covers, and assemblies where hand-tightening provides sufficient clamping force — typically light to moderate loads. The stainless steel shank provides good tensile strength for its diameter, but these are not rated for high-torque structural joints. For applications requiring specific torque values or load ratings, contact us to confirm suitability.

The rose red color is applied via anodizing, which is an electrochemical process that converts the aluminum surface into a durable oxide layer — it is not a paint or coating that sits on top. Anodized finishes resist chipping and peeling under normal handling. However, abrasive contact or harsh chemical exposure can wear the anodized layer over time. For indoor or light-duty outdoor use, the finish is expected to remain intact through normal service life.

The stainless steel shank offers good corrosion resistance in humid and mildly corrosive environments. The anodized aluminum head also resists oxidation. These screws are suitable for indoor use and sheltered outdoor applications. For direct exposure to saltwater, strong acids, or continuous moisture immersion, contact us to confirm compatibility with your specific environment.

Yes — M3, M3.5, and M4 variants are commonly used with T-slot nuts in 20-series and 30-series aluminum extrusion profiles. Verify that the T-slot nut thread matches your selected screw diameter. UNC 6#-32 is not a standard metric extrusion thread and is typically used with imperial-threaded inserts or tapped holes in rack equipment.

UNC 6#-32 has a nominal diameter of approximately 3.5 mm (0.138 in) with 32 threads per inch — it is an imperial standard. M3 has a nominal diameter of 3.0 mm with a 0.5 mm pitch — it is a metric standard. Although the diameters are close, the thread pitch and form are different and they will not engage correctly in each other's tapped holes. Always match the screw standard to your hardware.