M1.6 Knurled Thumb Screws – Carbon Steel Hand Grip Knob Bolts, 3–10mm, 0.35 Pitch

M1.6 is the nominal thread diameter: 1.6mm (approximately 0.063", or just over 1/16"). The 0.35mm pitch is the standard coarse pitch for M1.6 per ISO 68-1, equivalent to approximately 72.6 threads per inch.

This is one of the smallest standard metric thread sizes. To confirm compatibility:

• Measure your existing screw or tapped hole with digital calipers
• Use a thread pitch gauge to verify the 0.35mm pitch
• Check your assembly's BOM or engineering drawing for the specified thread callout

Choose the length based on your tapped hole depth and the material thickness being fastened. General guidelines:

• Minimum recommended thread engagement for M1.6: approximately 2.4mm (1.5× diameter)
• 3mm or 4mm: suited for thin panels (1–2mm) with shallow tapped holes
• 5mm or 6mm: general-purpose for medium panel thickness or moderate engagement depth
• 8mm or 10mm: for thicker assemblies, passing through a clearance hole into a nut, or where longer engagement is needed for a secure hold

When in doubt, measure your application before ordering. A screw that is too short will not engage enough threads; one that is too long may bottom out before clamping.

Two knob head configurations are available for the same M1.6 thread:

• 4mm wide × 4mm thick: compact, low-profile knob. Suited for tight spaces where clearance around the screw head is limited, such as densely populated PCB assemblies or narrow instrument panels.
• 8mm wide × 3.5mm thick: wider, flatter knob. Provides a larger gripping surface for easier hand-tightening, preferable when the assembly allows more clearance and you want a more comfortable grip.

Carbon steel generally offers higher tensile strength than aluminum alloy at the same thread size. However, at M1.6, all thumb screws — regardless of material — are designed for light-duty hand-tightening in precision assemblies, not for high-torque or structural load-bearing applications. The small thread cross-section limits the clamping force that can be safely applied. Finger-tight is typically sufficient and recommended to avoid stripping the threads.

Carbon steel is generally susceptible to rust and oxidation when exposed to moisture without a protective coating. These thumb screws are primarily intended for indoor use in electronics, instruments, and precision mechanical assemblies. For outdoor, high-humidity, or corrosive environments, a stainless steel or zinc-plated alternative would typically be more appropriate. Contact us if you need to discuss finish or material options for your specific application.

Yes. These screws follow the standard M1.6 × 0.35mm pitch metric coarse thread specification per ISO 68-1 / DIN 13, and are compatible with any standard M1.6 tapped hole or M1.6 hex nut. This is the most common and widely available thread pitch for M1.6 fasteners worldwide.

Common applications include:

• PCB mounting brackets and sensor housings in precision electronics
• Access panels on miniature instrument enclosures
• Optical equipment and camera accessories
• Small robotics, drone frames, and RC model components
• Eyeglass frame repairs and small consumer electronics
• Any assembly where a very small metric fastener needs to be hand-tightened without tools

Yes. Each size and head configuration is available in quantities of 1, 2, 5, 10, 20, or 50 pieces. Ordering 1 or 2 pieces first is a practical way to verify thread fit, head clearance, and length before committing to a larger quantity for production or repair stock.