Black M3/4/5/6/8/10 Knurled Thumb Screws, Aluminum Handle + Stainless Thread Rod

Match the thread size (M3, M4, M5, M6, M8, or M10) to the tapped hole or nut already in your assembly. If you are designing a new panel, M4 and M5 are the most common choices for light-duty enclosures, while M6 and M8 suit heavier structural panels. Always verify the thread pitch of your existing hardware before ordering.

Measure the total clamping thickness — the combined depth of the panel, any spacers, and the nut or threaded insert — then add 3–5 mm for thread engagement. For example, a 10 mm panel with a 5 mm nut would typically need a shaft length of at least 15–18 mm. Available lengths run from 6 mm to 135 mm, so most configurations are covered.

D12 mm heads fit in tight spaces where clearance around the fastener is limited, such as densely populated PCB enclosures. D16 mm offers a balance of grip area and compactness. D20 mm provides the most torque leverage for hand-tightening and is the easiest to grip with gloved hands. Choose based on the clearance available and how frequently the fastener will be operated.

These fasteners are designed for panel access, fixture adjustment, and light-duty clamping — not for primary structural joints under dynamic or high-shear loads. The stainless steel rod provides solid thread strength for hand-tightened applications, but for vibration-prone or load-bearing assemblies, a thread-locking compound or a secondary locking nut is recommended.

Stainless steel and aluminum can experience galvanic corrosion in wet environments over extended periods. For indoor or dry workshop use, this is not a practical concern. For outdoor or high-humidity applications, applying a thin layer of anti-seize compound to the threads before installation will prevent galling and make future removal easier.

Yes. These knurled thumb screws are widely used for bed-leveling adjustments on FDM 3D printers (typically M3 or M4), CNC machine guard panels (M5 or M6), and optical rail fixtures. The knurled grip allows repeatable micro-adjustments by hand without tools, which is particularly useful for frequent calibration tasks.

Each variant is sold in 1-piece, 5-piece, or 10-piece packs for a single thread size and head size combination. To mix sizes — for example, M4×15 and M5×20 — add each size as a separate line item to your cart. There is no minimum order across sizes.