M3 Brass Hex Bolts That Won’t Let You Down
For most hobbyists and builders, the M3-0.5 x 8mm Brass Hex Bolts from Hillman are the top pick because they offer a precise fit and reliable corrosion resistance. Their main advantage is consistent quality at a low price, but they lack a coating for extra protection in harsh environments.
Brass hex bolts are a staple for fastening components in electronics, RC models, and custom builds. Their non-magnetic and corrosion-resistant nature makes them ideal for projects where steel is not suitable.
We compared seven popular M3 brass hex bolts based on user feedback and specifications. Look for exact thread pitch and length tolerances to avoid stripped threads or loose fits.
What matters most
Our top picks
Hillman Brass Hex Bolt, M3-0.5 x 8mm
Hillman’s M3 brass hex bolts are a reliable choice for everyday fastening. They come in a pack of 20 with a clean 8mm length. Owners report consistent threading and a snug fit in standard M3 nuts.
Pros
- Consistent quality
- Corrosion resistant
- Affordable
Cons
- No coating
- Limited length options
M3-0.5 x 10mm Brass Hex Bolts (50-Pack) by A2Z Fasteners
This 50-pack from A2Z Fasteners offers a cost-effective solution for builders who need many bolts. The 10mm length is versatile for joining thicker parts. Users say the brass is genuine and machines well.
Pros
- Great per-unit price
- Accurate threading
- Good for prototyping
Cons
- May have minor burrs
- Not individually packaged
M3-0.5 x 6mm Brass Hex Bolts (100-Pack) by uxcell
uxcell offers a 100-pack of 6mm brass hex bolts, perfect for tight spaces. The short length works well for PCB standoffs and small enclosures. Reviewers mention they are slightly softer than steel but adequate for light duty.
Pros
- High count
- Short length for tight spots
- Non-magnetic
Cons
- Not for high torque
- May strip if over-tightened
M3-0.5 x 12mm Brass Hex Bolts (25-Pack) by Bolt Dropper
Bolt Dropper’s 12mm brass hex bolts provide extra length for thicker assemblies. The 25-pack is a moderate quantity. Users appreciate the clean finish and accurate threads.
Pros
- Longer length
- Smooth finish
- Good tolerance
Cons
- Fewer per pack
- Not as many size options
M3-0.5 x 5mm Brass Hex Bolts (200-Pack) by Hilitchi
Hilitchi provides a huge 200-pack of 5mm brass hex bolts. This is ideal for production runs or stocking up. The tiny length suits very thin panels. Some buyers note variance in thread finish.
Pros
- Extremely economical
- Non-magnetic
- Decent quality for price
Cons
- Very short length
- Inconsistent finish
M3-0.5 x 16mm Brass Hex Bolts (10-Pack) by FastenMaster
FastenMaster’s 16mm brass hex bolts are among the longest M3 options. They are useful for reaching through multiple layers. The 10-pack is smaller but each bolt is made with precision.
Pros
- Long length
- High strength for brass
- Clean threads
Cons
- Higher cost per bolt
- Limited packaging
M3-0.5 x 20mm Brass Hex Bolts (5-Pack) by MicroFasteners
MicroFasteners offers extra-long 20mm brass hex bolts for unique projects. The 5-pack is small, but precision is high. These are often used in model building and custom fixtures.
Pros
- Extra long for special uses
- High precision
- Good surface finish
Cons
- Very expensive per bolt
- Not for everyday use
Side by side
| # | Model | Thread Size | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | Hillman Brass Hex Bolt, M3-0.5 x 8mm | M3 x 0.5 | General purpose electronics and hobby projects | 9.4 | Check price |
| 2 | M3-0.5 x 10mm Brass Hex Bolts (50-Pack) by A2Z Fasteners | M3 x 0.5 | Bulk purchases for multiple projects | 9.1 | Check price |
| 3 | M3-0.5 x 6mm Brass Hex Bolts (100-Pack) by uxcell | M3 x 0.5 | Small electronics and circuit boards | 8.9 | Check price |
| 4 | M3-0.5 x 12mm Brass Hex Bolts (25-Pack) by Bolt Dropper | M3 x 0.5 | Projects requiring extra grip length | 8.7 | Check price |
| 5 | M3-0.5 x 5mm Brass Hex Bolts (200-Pack) by Hilitchi | M3 x 0.5 | High-volume small fastening needs | 8.5 | Check price |
| 6 | M3-0.5 x 16mm Brass Hex Bolts (10-Pack) by FastenMaster | M3 x 0.5 | Custom mounts and brackets | 8.3 | Check price |
| 7 | M3-0.5 x 20mm Brass Hex Bolts (5-Pack) by MicroFasteners | M3 x 0.5 | Specialty long-reach applications | 8.0 | Check price |
Common questions
Are M3 brass hex bolts strong enough for metal framing?
Brass is softer than steel, so M3 brass bolts are not recommended for structural metal framing. They are best for light-duty applications like electronics, models, and decorative fixtures.
Can I use M3 brass bolts outdoors?
Brass resists corrosion and rust, so it can be used outdoors. However, it may tarnish over time. For harsh environments, consider a protective coating or use stainless steel.
What is the standard thread pitch for M3 bolts?
The standard thread pitch for M3 bolts is 0.5mm. Some specialty bolts may have a different pitch, but 0.5mm is the most common for metric M3.
How do I know which length to buy?
Measure the combined thickness of the materials you are bolting together. Add a few millimeters for the nut and washer. Choose the next standard length that exceeds that measurement.
Do brass bolts require lubrication?
Brass is naturally somewhat self-lubricating, but a small amount of anti-seize compound can help prevent galling, especially when threading into brass or aluminum.
Can I use M3 brass bolts with a 3D printed part?
Yes, brass bolts work well with plastic parts. They are non-magnetic and won’t interfere with electronics. Just avoid overtightening to prevent stripping the plastic threads.
Are M3 brass bolts electrically conductive?
Brass is a good conductor of electricity. If you need electrical insulation, use nylon or plastic washers and ensure the bolt doesn’t contact live circuits unintentionally.
What tools do I need to install M3 hex bolts?
You will need a hex wrench or socket that fits the head size, typically 2.5mm or 3mm. A small torque wrench is useful to avoid overtightening.
Our pick
For most users, the Hillman M3-0.5 x 8mm brass hex bolts are the best choice due to their balance of quality and affordability. If you need a bulk supply for various projects, the A2Z Fasteners 50-pack offers great value. For specialized long lengths, FastenMaster and MicroFasteners provide precision options, but at a higher cost.
