1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer
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1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer1/4 - 20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors - HomeDIYer

1/4-20 UNC Knurled Thumb Screws – Step Hand Grip Knob Bolts, Head Width 20mm, 10 Colors

HomeDIYer
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By HomeDIYer®

Price:
$2.98 USD
Stock:
In stock (500 units), ready to be shipped

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Description

1/4-20 UNC Knurled Thumb Screws — Tool-Free Fastening with Step Hand Grip Knob

If you've ever fumbled for a wrench mid-project or stripped a fastener trying to hand-tighten a standard bolt, you know the frustration. These 1/4-20 UNC knurled thumb screws are built for makers, machinists, woodworkers, and DIYers who need fast, repeatable, tool-free adjustments on jigs, fixtures, panels, and assemblies.

Each screw features a 20mm-wide stepped knurled knob head with a tiered grip profile that gives your fingers multiple contact points for confident tightening — even with work gloves on. The 1/4-20 UNC thread is one of the most widely used fastener standards in the US, ensuring broad compatibility. Available in 23 lengths from 6mm (≈1/4") to 100mm (≈3-15/16"), and in 10 anodized colors including Black, Silver, Royal Blue, Green, Golden, Dark Red, Purple, Rose Red, Sky Blue, and Orange.

Typical use cases include CNC router jig clamping, woodworking fixture hold-downs, electronics enclosure panels, 3D printer frame adjustments, and any application where quick-release hand-tightened fasteners improve workflow. The step grip knob design reduces hand fatigue during repeated adjustments — a practical advantage for production jig setups and workshop environments.

🔩 Thread Compatibility: 1/4-20 UNC — fits any standard 1/4-20 UNC nut, T-nut, threaded insert, or tapped hole. Widely used in US woodworking, machining, and DIY applications.

✅ Key Features of These 1/4-20 UNC Knurled Thumb Screws

  • ✋Step Hand Grip Knob Design — The tiered, knurled 20mm head provides multiple finger contact points for secure hand-tightening without tools, reducing slippage during repeated adjustments.
  • 📏23 Length Options (6mm–100mm) — From short 6mm (≈1/4") panel fasteners to long 100mm (≈3-15/16") fixture bolts, one listing covers a wide range of clamping depths and material thicknesses.
  • 🎨10 Anodized Color Options — Color-code your jig setups or match your workshop aesthetic. All colors share identical thread specs and dimensional tolerances.
  • 🔗Standard 1/4-20 UNC Thread — Compatible with the most common US fastener standard, including T-nuts, threaded inserts, and tapped aluminum or steel fixtures used in CNC router jig clamping and workholding.
  • 🛠️Broad Application Range — Suited for woodworking fixtures, electronics enclosures, 3D printer frames, machine guards, and any assembly requiring quick-release hand-tightened fasteners.
  • 📦Sold Individually — Mix and Match — Order exactly the quantity, length, and color you need. No forced bulk packs; ideal for prototyping, repairs, or topping up your fastener stock.

📐 Technical Specifications — 1/4-20 UNC Knurled Thumb Screw

Thread Size 1/4-20 UNC (Unified National Coarse)
Thread Diameter 1/4" (≈6.35mm)
Thread Pitch 20 TPI (threads per inch)
Knob Head Width 20mm (≈25/32")
Grip Style Stepped knurled hand grip knob
Available Lengths (L) 6mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm
Length Range (Imperial) ≈1/4" to ≈3-15/16"
Available Colors Royal Blue, Green, Golden, Dark Red, Black, Silver, Purple, Rose Red, Sky Blue, Orange
Material / Finish See variant options
Drive Type Hand-tightened (no tool required)
Quantity per Order 1 piece (sold individually)
Compatible Standards 1/4-20 UNC nuts, T-nuts, threaded inserts, tapped holes
Country of Origin Contact us to confirm
⚠️ Note: Length (L) refers to the threaded shank length, not the overall height including the knob. Please verify your required thread engagement depth before ordering. If unsure, contact us to confirm.

❓ Frequently Asked Questions

How do I choose the right length for my application?

Measure the total material thickness you need to clamp or fasten, then add the thread engagement depth — generally at least 1× the thread diameter (1/4" ≈ 6mm). For example, clamping 10mm of material typically calls for a length of 16–20mm. Available lengths range from 6mm (≈1/4") to 100mm (≈3-15/16"). When in doubt, choose the next size up.

What is the clamping or load capacity of these thumb screws?

These are designed for hand-tightened, tool-free applications such as jigs, fixtures, panels, and light assemblies. They are not rated for structural or high-torque loads. For heavy clamping, a standard hex bolt with a wrench is generally recommended.

Are these thumb screws suitable for outdoor or corrosion-prone environments?

The colored anodized or coated finish provides a degree of surface protection, but these screws are not specifically rated for prolonged outdoor or marine exposure. For outdoor use, we recommend applying a light coating of anti-corrosion lubricant or contacting us to confirm material suitability.

What thread standard do these use, and what nuts or inserts are compatible?

These use the 1/4-20 UNC (Unified National Coarse) thread standard, which is one of the most common thread sizes in the US. They are compatible with any standard 1/4-20 UNC nut, threaded insert, T-nut, or tapped hole — including those used in CNC router tables and aluminum extrusion fixtures.

What is the head width and what does the step grip design mean?

The knob head is 20mm wide and features a stepped, knurled profile — meaning the grip surface has a tiered shape that provides multiple contact points for your fingers, making it easier to tighten or loosen without tools, even with gloves on.

Can I use these in CNC router jigs or woodworking fixtures?

Yes. These 1/4-20 UNC knurled thumb screws are commonly used in CNC router jigs, woodworking fixtures, and workholding setups where quick, tool-free adjustments are needed. The step grip knob allows fast repositioning without reaching for a wrench.

How do I select the right color?

Color is purely aesthetic and does not affect function or thread specification. Many users choose a specific color to color-code different fixture setups or simply for visual preference. All 10 colors share the same 1/4-20 UNC thread and dimensional specs.

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

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