3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob
3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob
3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob
3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob
3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob
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3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob

3/8"-16 UNC Knurled Thumb Screws – Aluminum Shoulder Bolt, High-Type Hand Grip Knob

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By HomeDIYer®

Price:
$10.47 USD
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In stock (500 units), ready to be shipped

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Description

 

3/8"-16 UNC Knurled Thumb Screws — Tool-Free Fastening for Jigs, Fixtures & Enclosures

If you've ever stripped your knuckles reaching for a hex key just to make a quick panel adjustment, you know the frustration. Machinists, woodworkers, electronics builders, and DIY enthusiasts who work with frequently adjusted fixtures need a fastener they can tighten and release by hand — reliably, repeatedly, and without tools. These 3/8"-16 UNC knurled thumb screws are built for exactly that workflow.

Each screw features a high-type aluminum knurled knob with a shoulder bolt design, giving you a wide, textured grip surface that's easy to turn even with slightly oily or gloved hands. Available in lengths from 50mm (≈2") to 100mm (≈3-15/16"), with 10 anodized color options and pack quantities of 1 or 2 pieces per order. The 3/8"-16 UNC thread is one of the most widely used inch-series coarse thread standards in North America.

Typical use cases include CNC router jig clamping, 3D printer enclosure panels, electronics chassis assembly, woodworking fence adjustments, and laboratory fixture setups — anywhere you need a knurled thumb screw for hand-tightened fastening without reaching for a tool.

🔩 Thread Compatibility: Fits any standard 3/8"-16 UNC tapped hole or hex nut. Not compatible with metric threads. Confirm your hole thread standard before ordering.

✅ Key Features of These 3/8"-16 UNC Knurled Thumb Screws

  • ✋High-Type Knurled Knob — The tall, wide knurled head provides a firm hand grip for tool-free tightening and loosening, reducing fatigue during repeated adjustments on jigs and fixtures.
  • ⚖️Lightweight Aluminum Construction — Made from aluminum alloy, these screws add minimal weight to your assembly — ideal for weight-sensitive applications like enclosures, panels, and portable fixtures.
  • 📏Wide Length Range — Available in 11 lengths from 50mm (≈2") to 100mm (≈3-15/16"), measured excluding the head, so you can match the screw to your exact grip depth without guessing.
  • 🎨10 Anodized Color Options — Choose from Royal Blue, Green, Golden, Dark Red, Black, Silver, Purple, Rose Red, Sky Blue, and Orange — useful for color-coding fasteners by function or location on multi-point fixtures.
  • 🔗Shoulder Bolt Design — The shoulder bolt profile provides a smooth unthreaded shank section that can act as a locating pin or pivot point in certain fixture and jig applications.
  • 🇺🇸UNC Thread Standard — The 3/8"-16 UNC thread is one of the most common coarse-thread inch standards in North America, ensuring broad compatibility with existing tapped holes and hardware.

📐 Technical Specifications — 3/8"-16 UNC Knurled Thumb Screws

Thread Standard 3/8"-16 UNC (Unified National Coarse)
Thread Diameter 3/8" (≈9.525mm)
Thread Pitch 16 TPI (≈1.588mm pitch)
Shank Length (Excluding Head) 50mm (≈2") / 55mm / 60mm / 65mm / 70mm / 75mm / 80mm / 85mm / 90mm / 95mm / 100mm (≈3-15/16")
Head Style High-type knurled knob
Drive Style Hand-tightened (no tool required)
Bolt Type Shoulder bolt
Material Aluminum alloy
Finish / Color Anodized — see variant options
Pack Quantity 1 Pcs or 2 Pcs (see variant options)
Compatible Hole Thread 3/8"-16 UNC tapped hole or nut
Metric Thread Compatibility Not compatible — UNC inch-series only
⚠️ Note: Shank length is measured excluding the knob head. Please verify your required grip length before selecting a size. If you are unsure, contact us to confirm.

❓ Frequently Asked Questions

How do I choose the right length for my thumb screw?

Measure the total grip depth of the parts you need to clamp or fasten, then add the thread engagement length — generally at least 1× the screw diameter (about 3/8" or ~9.5mm) for aluminum. For example, if your panel stack is 40mm (≈1-9/16") thick, a 50mm (≈2") screw typically provides enough thread engagement. When in doubt, size up.

What material are these thumb screws made from?

These thumb screws are made from aluminum alloy. Aluminum is lightweight, corrosion-resistant in most indoor environments, and easy to grip by hand — making it well-suited for tool-free adjustments on jigs, fixtures, and enclosures.

Are these thumb screws suitable for outdoor use?

Aluminum generally offers good corrosion resistance in mild outdoor conditions. However, for prolonged exposure to moisture, salt spray, or harsh chemicals, additional protection (such as anodizing or a protective coating) is typically recommended. Contact us to confirm suitability for your specific environment.

What thread standard do these screws use, and what holes are they compatible with?

These screws use the 3/8"-16 UNC (Unified National Coarse) thread standard — one of the most common inch-series thread standards in the US. They are compatible with any standard 3/8"-16 UNC tapped hole or nut. They are not compatible with metric threads.

How much clamping force can these thumb screws handle?

As hand-tightened fasteners, these thumb screws are designed for tool-free, low-to-moderate clamping applications — typically used on jigs, fixtures, enclosures, and panels where frequent adjustment is needed. For high-torque or structural load-bearing applications, a wrench-driven fastener is generally more appropriate.

Can I use these with metric-threaded holes?

No. These are 3/8"-16 UNC inch-series screws and are not compatible with metric threads. For metric applications, please check our other listings or contact us for guidance.

What is the difference between the 1Pcs and 2Pcs pack options?

The 1Pcs option includes a single thumb screw, while the 2Pcs option includes two screws of the same size and color. The 2Pcs pack is a cost-effective choice when you need matching pairs for symmetric fixtures or dual-point clamping setups.

🛒 Select your size, color, and pack quantity above, then add to cart — ships from our US warehouse.

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