🔧 Product Overview: 3/8-16UNC Knurled Thumb Screws – Aluminum Alloy Shank + Stainless Steel Hand Grip (6–100mm)
For heavy‑duty hand‑tightening applications where a large, comfortable grip is essential, these 3/8-16UNC knurled thumb screws combine a strong aluminum alloy threaded shank with a stainless steel knurled grip. The stainless steel hand grip provides a durable, non‑slip surface for tool‑less operation, while the aluminum shank keeps the overall weight manageable. Fully threaded with standard UNC coarse pitch (16 TPI), available in thread lengths from 6mm to 100mm. The anodized aluminum finish offers good corrosion resistance. Ideal for machinery, precision molds, bearing assembly, and industrial equipment where frequent manual adjustments are required.
✨ Why These Dual‑Material Knurled Thumb Screws Are a Workshop Essential
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Dual‑material construction – Stainless steel knurled head provides a durable, slip‑resistant grip. Aluminum alloy threaded shank keeps weight low while offering good strength.
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Tool‑less operation – The diamond knurled surface gives you a secure, non‑slip grip for hand tightening and loosening – no wrench needed.
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3/8-16UNC thread (imperial) – Standard coarse UNC thread (16 threads per inch). Common in machinery, molds, and industrial equipment.
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Wide thread length range: 6mm to 100mm – Available in multiple lengths (6, 8, 10, 12, 15, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100mm). Choose exactly what your application needs.
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Fully threaded, coarse UNC pitch – Threads run the entire length for maximum grip and easy nut engagement.
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Smooth, burr‑free workmanship – Clean threads and even force distribution. High‑quality materials for anti‑corrosion and rust resistance.
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Wide applications – Machinery, precision molds, bearing assembly, industrial equipment, jigs, and fixtures.
📏 Technical Specifications – 3/8-16UNC Knurled Thumb Screws
| Specification |
Details |
| Product Type |
Knurled Thumb Screws (Hand Grip Knob Bolts) |
| Thread Size |
3/8-16UNC (Unified National Coarse, 16 TPI) |
| Thread Length Range (under head) |
6mm – 100mm (select from options: 6,8,10,12,15,18,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100mm) |
| Thread Type |
Fully threaded |
| Length Measurement |
Under head – from underside of head to tip (head not included) |
| Head Material |
Stainless steel (knurled hand grip) |
| Shank Material |
Aluminum alloy (anodized) |
| Head Style |
Knurled cylindrical (diamond knurl) |
| Drive Style |
Hand grip (toolless) |
| Tolerance |
±2.0mm |
❓ FAQs – 3/8-16UNC Knurled Thumb Screws
🔸 What is the advantage of the stainless steel hand grip?
The stainless steel knurled head is extremely durable, corrosion‑resistant, and provides a secure non‑slip grip even with oily or gloved hands. It will not wear out like plastic or aluminum grips under heavy use.
🔸 How is thread length measured? Which length should I choose?
Thread length is measured from the underside of the head to the tip (head not included). For standard panels (5‑10mm thick), choose a length 5‑10mm longer than the panel thickness to allow for nut engagement. For pre‑tapped holes, measure the hole depth and select a length slightly shorter than that depth.
🔸 Are these screws fully threaded? What is the thread pitch?
Yes – they are fully threaded from under the head to the tip. The thread is 3/8-16UNC, which means 16 threads per inch (coarse thread).
🔸 Will the aluminum shank gall when threaded into steel?
Aluminum on steel can gall if installed dry at high speed, but since these are hand‑tightened, the risk is low. For repeated use or high torque, apply a light lubricant or anti‑seize to the threads. The anodized finish also helps reduce friction.
🔸 Can I use these screws with nuts, or are they for tapped holes only?
These are standard machine screws – they work with matching 3/8-16UNC nuts or in pre‑tapped holes. For through‑hole applications, use a nut on the back side. The knurled head is designed for hand grip only – do not use tools on the knurling.
🔸 What colors are available for the aluminum shank?
The aluminum shank is anodized and available in various colors – please select your preferred color from the dropdown options. Common colors include Black, Silver, Red, Blue, and Gold. Note that colors may vary slightly due to lighting.
