M2–M6 Stainless Steel Knurled Thumb Screws — Cylinder Head Hand Grip Knob Bolts

Match the thread diameter (M2, M3, M4, M5, or M6) to your tapped hole or nut size. For length, the screw should engage at least 1.5× the thread diameter into the mating part — for example, an M4 screw typically needs at least 6mm of thread engagement. If you need help converting: 10mm ≈ 3/8", 16mm ≈ 5/8", 20mm ≈ 25/32".

These are designed for hand-tightened, tool-free applications. They generally provide sufficient clamping force for panel covers, access doors, electronics enclosures, and light-duty fixtures. For high-torque or structural connections, a tool-driven fastener is typically recommended.

Yes. Stainless steel offers good corrosion resistance and is generally suitable for outdoor, humid, or mildly corrosive environments. For highly aggressive chemical exposure or marine applications, confirm the specific grade with us before ordering.

These are metric fasteners following ISO/DIN standards (M2 through M6). They are not compatible with UNC or UNF imperial threads. Ensure your tapped holes or nuts are metric before ordering.

Yes, in most cases. Thumb screws work well with heat-set inserts in plastic or directly into tapped plastic for low-stress applications. For repeated removal cycles, a brass or stainless heat-set insert is generally recommended to prevent thread wear.

We offer quantities from 1 to 500 pieces per size. For prototyping or single repairs, the 1–10 pcs options work well. For production runs or workshop stock, the 50–500 pcs tiers offer better per-unit value. Mix sizes as needed — each size/quantity combination is a separate variant.

These feature a cylinder (low-profile round) head with a knurled outer surface designed for finger-tightening — no driver required. The knurling pattern provides grip even with slightly oily or gloved hands.