M3.5 x4-20mm Knurled Thumb Screws Aluminium Alloy Hand Grip Knob Bolts High Type

The listed length (e.g., 4 mm, 10 mm) refers only to the threaded shank — the portion that enters the tapped hole or threaded insert. It does not include the height of the knob head. To determine the length you need, measure the depth of your tapped hole or the thickness of the material being fastened, then select the closest shaft length that fits without bottoming out.

Yes. These screws use a standard M3.5 metric thread and are compatible with M3.5 tapped holes and heat-set or press-fit M3.5 threaded inserts commonly used in 3D-printed and machined parts. Always verify the thread pitch of your existing hardware matches before ordering.

Aluminium alloy thumb screws are suited for light-to-moderate clamping loads applied by hand. They are not intended for high-torque or structural fastening applications. For panels, covers, and access doors that are opened and closed regularly, aluminium thumb screws perform reliably over many cycles. Avoid over-tightening, which can strip the threads in softer materials like plastic.

Anodizing creates an aluminium oxide layer that resists surface oxidation and light abrasion in typical indoor environments. It is not rated for prolonged exposure to salt spray, harsh chemicals, or outdoor weathering. For outdoor or high-humidity applications, consider stainless steel alternatives or apply additional protective measures.

The 1-piece option is useful when you need a single replacement screw or are prototyping a design with one fastener point. The 5-piece pack offers a lower per-unit cost and is practical for production builds, multi-point panel fastening, or keeping spares on hand. Both options are available for every size and colour combination.

Yes — these are a common choice for 3D printer side panels, electronics enclosures, and DIY project boxes where tool-free access is needed. The M3.5 thread fits many standard M3.5 inserts used in printed parts. Select a shaft length that matches your panel thickness plus insert depth, leaving a small clearance to avoid bottoming out.

The colour difference is cosmetic and functional for identification purposes. All colour variants share the same aluminium alloy construction and M3.5 thread specification. Colour-coding is useful in multi-zone assemblies where different fastener locations need to be visually distinguished at a glance — for example, using one colour for power-side panels and another for signal-side covers.