Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs
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Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip KnobsBrass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs

Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight & Grip Knobs

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By HomeDIYer®

Price:
$1.99 USD
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In stock (500 units), ready to be shipped

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Description

 

M3×4.5mm Brass Knurled Thumb Screws — Tool-Free Fastening for Slingshot Sights & Grip Knobs

Anyone who has fumbled for a screwdriver mid-adjustment on a slingshot sight or optical mount knows the frustration. These M3×4.5mm brass knurled thumb screws are designed for exactly those moments — quick, tool-free tightening and loosening with a confident finger grip, whether you are in the field or at the workbench.

Each screw features a flat knurled head in solid brass, with an M3 metric thread and a 4.5mm (approximately 3/16") shank length. Available in natural brass finish and nickel-plated brass, sold in packs of 2, 5, 10, 20, 50, or 100 pieces to suit both single-project needs and workshop stock.

Typical applications include slingshot sight windage and elevation adjustments, hand-grip knob assemblies, instrument panel fasteners, 3D printer bed leveling screws, and any light-duty mechanism where repeated hand-tightening is needed without tools.

🔩 Compatibility: M3 metric thread (standard M3×0.5mm pitch). Not compatible with imperial #4-40 or #6-32 threads. Confirm your application uses M3 metric threading before ordering.

✅ Key Features of These M3 Brass Knurled Thumb Screws

  • ✋Knurled Flat Head for Finger Control — The circumferential knurling pattern gives a secure grip for hand-tightening, making these ideal as tool-free adjustment screws in slingshot sights and optical mounts.
  • 🟡Solid Brass Construction — Brass offers inherent corrosion resistance, electrical conductivity, and a non-magnetic profile — useful in sensitive instrument and electronics enclosure applications.
  • 🪙Nickel-Plated Option Available — The Ni-plated variant adds a silver-toned finish with increased surface hardness and tarnish resistance, suitable for applications where appearance consistency matters.
  • 📐Compact M3×4.5mm Shank — The short 4.5mm (≈3/16") grip length suits shallow threaded holes common in slingshot frames, camera accessories, and lightweight DIY fixtures.
  • 📦Flexible Pack Quantities — Order from 2pcs up to 100pcs. Larger packs reduce per-piece cost, making them practical for bulk thumb screw restocking or multi-unit production runs.
  • 🚚Ships from US Warehouse — Stocked domestically for faster delivery across the contiguous United States, with no extended international transit times.

📐 Technical Specifications — M3 Flat Knurled Thumb Screws

Thread Standard Metric M3
Thread Pitch 0.5mm (standard M3 coarse pitch)
Shank Length 4.5mm (≈3/16")
Head Style Flat knurled (circumferential knurl pattern)
Head Diameter See variant options
Head Height See variant options
Material Brass (CuZn alloy)
Finish Options Natural brass / Nickel-plated brass
Drive Type Hand-tighten (knurled head); flat-blade compatible
Pack Quantities 2 / 5 / 10 / 20 / 50 / 100 pcs
Applicable Standard Contact us to confirm
Country of Origin Contact us to confirm
⚠️ Heads up: Head diameter and height dimensions are not listed above. If your application has tight clearance requirements, please contact us to confirm exact head dimensions before ordering.

❓ Frequently Asked Questions

What does M3×4.5mm mean, and how do I confirm this is the right size?

M3 refers to a 3mm nominal thread diameter (approximately 0.118"). The 4.5mm (approximately 3/16") is the grip length — the threaded shank length below the head. Measure your threaded hole depth and clearance before ordering. If you need a longer shank, see our other thumb screw listings.

How strong are these thumb screws? Can they handle vibration?

Brass thumb screws are generally suitable for light-duty clamping and adjustment applications. They are not intended for high-torque or structural load-bearing use. For vibration-prone assemblies, consider adding a lock washer or thread-locking compound.

Can these be used outdoors or in humid environments?

Brass has naturally good corrosion resistance compared to plain steel. The nickel-plated variant offers additional surface protection against moisture and mild chemicals. For prolonged outdoor exposure, applying a light coat of protective oil is generally recommended.

What thread standard do these use — metric or imperial?

These are metric M3 thread screws with a standard M3 pitch (typically 0.5mm). They are not compatible with imperial #4-40 or #6-32 threads. Confirm your equipment uses M3 metric threading before ordering.

What is the difference between the natural brass and the nickel-plated version?

Both variants share the same M3×4.5mm dimensions and knurled flat-head design. The natural brass has a warm golden appearance and develops a patina over time. The nickel-plated version has a silver-toned finish with added surface hardness and slightly better resistance to tarnishing.

Which pack size should I order?

For single-device adjustments (e.g., one slingshot sight), 2–5pcs is typically sufficient. For workshop stock or multi-unit builds, the 20–100pcs packs offer a lower per-piece cost. Check the price-per-piece across pack sizes to find the best value for your project.

Do I need any tools to install these thumb screws?

No tools are required for typical hand-tightening applications — that is the primary purpose of the knurled head design. The knurling pattern provides grip for finger-tightening. If additional torque is needed, a flat-blade screwdriver can generally be used on the head rim.

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

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