M6 M8 M10 M12 T-Handle Thumb Screws — Wing Knob Clamping Bolts with Flange Nut

Measure the total thickness of the material you need to clamp, then add the thread engagement depth — typically 1–1.5× the bolt diameter. For example, clamping 20mm of material with an M8 bolt generally calls for a length of 30–35mm (≈1.2–1.4"). Available lengths run from 10mm (≈3/8") to 100mm (≈3-15/16"). When in doubt, size up — a slightly longer bolt can always be used with a spacer or washer.

These thumb screws use standard ISO metric coarse threads (M6, M8, M10, M12), compatible with most metric tapped holes, hex nuts, T-nuts in aluminum extrusion profiles (2020/3030/4040), and threaded inserts used in machinery, woodworking jigs, and 3D-printer frames. They are not compatible with UNC/UNF inch-standard threads.

These T-handle thumb screws are generally manufactured from zinc alloy or engineering-grade composite, providing a balance of rigidity and a hand-friendly grip surface. The exact material may vary by size. Contact us to confirm the material specification for your selected variant before ordering for load-critical applications.

Zinc alloy variants typically offer moderate corrosion resistance suitable for indoor and sheltered outdoor use. For prolonged outdoor exposure or high-humidity environments (e.g., outdoor enclosures, marine workshops), we recommend applying a light anti-corrosion spray periodically. Contact us to confirm the surface finish of your specific variant if corrosion resistance is a primary concern.

The flange (D) is the wide disc at the base of the knob that bears against the workpiece surface and distributes clamping load. Three sizes are available:

• D55mm (≈2.17") — compact footprint, ideal for tight spaces or hard materials
• D65mm (≈2.56") — general-purpose balance of grip area and clearance
• D75mm (≈2.95") — maximum load distribution, best for softer materials or wide clamping pads

In general, choose a larger flange when clamping softer materials (wood, plastic, foam) to prevent surface indentation.

Hand-tightened clamping torque varies by thread size and individual grip strength. As a general reference, M8 variants typically achieve 3–6 Nm by hand, while M12 variants can reach 8–12 Nm. These values are sufficient for most jig-positioning and fixture-retention tasks. For applications requiring precise or higher torque, contact us for load specifications or use a torque wrench on the shank if accessible.

Yes. The standard ISO metric thread pattern makes these thumb screws widely compatible with aluminum extrusion T-slot frames (2020, 3030, 4040 profiles), CNC router jig clamping plates, woodworking bench fixtures, and 3D printer enclosure panels — anywhere a tool-free hand-tighten fastener needs to be adjusted frequently. Match the thread size (M6/M8/M10/M12) to your T-nut or tapped hole specification.

Both options ship the identical thumb screw. The 5pcs pack offers a lower per-unit cost and is ideal for projects requiring multiple clamping points simultaneously — such as router table fences, jig setups with several hold-downs, or machine enclosures with multiple access panels. The 1pcs option is best for single replacements or testing fit before a larger order.