Top M4 Brass Hex Bolts for Corrosion-Resistant Fastening
For most builders, the Hilitchi M4 Brass Hex Bolts stand out as the top pick due to their consistent quality and broad compatibility. They suit electrical work, model making, and marine repairs where corrosion resistance matters. Their main limitation is that they lack a built-in washer, so you may need to purchase separately for some applications.
Brass hex bolts are essential for projects where corrosion resistance and conductivity are priorities. The M4 size is common in electronics, automotive, and hobbyist applications. Choosing the right set ensures a secure fit and long-lasting performance.
This roundup covers top-selling M4 brass hex bolts on Amazon, highlighting their strengths and potential drawbacks. We analyzed specifications and owner reports to help you select the best option for your specific needs.
Our top picks
Hilitchi M4 Brass Hex Bolts, 20mm Length, 50 Pack
These bolts are made from high-quality C36000 brass, offering excellent corrosion resistance and electrical conductivity. They feature clean, precise threads that engage smoothly with standard M4 nuts. The 50-pack provides ample supply for multiple projects. Owners report minimal burrs and consistent dimensions.
Pros
- High corrosion resistance
- Consistent thread quality
- Good value for bulk purchase
Cons
- No washers included
- Length may be too long for some applications
LYD M4 Brass Hex Bolts, 16mm Length, 20 Pack
A shorter alternative ideal for confined spaces. Made from free-machining brass, these bolts offer good strength and easy installation. The 16mm length suits PCB mounting and small enclosures. Users note that the hex head provides a secure grip for wrenches.
Pros
- Compact length
- Smooth threading
- Good for electronics
Cons
- Smaller pack size
- Not suitable for thicker materials
LYD M4 Brass Hex Bolts, 30mm Length, 10 Pack
When you need extra length for thicker components, these 30mm bolts come in handy. They are fully threaded and made from durable brass. Ideal for custom mounts or fixtures. Some users report that the longer length can bend if over-torqued, so use appropriate care.
Pros
- Extra length for versatility
- Full threading
- Corrosion resistant
Cons
- Small quantity
- Potential bending under stress
LYD M4 Brass Hex Bolts, 12mm Length, 50 Pack
This bulk pack is budget-friendly without sacrificing quality. Each bolt is precision-machined from brass and features a clean finish. Great for hobbyists who go through many fasteners. The 12mm length is versatile for many DIY tasks.
Pros
- Cost-effective per bolt
- Good quality
- Common size
Cons
- Length may be short for some
- No storage case
LYD M4 Brass Hex Bolts, 10mm Length, 100 Pack
These short 10mm bolts are perfect for securing small components in tight spots. The high quantity makes them a staple for electronics repair and model building. Owners appreciate the clean, uniform threads.
Pros
- Large quantity
- Short length for compact use
- Consistent quality
Cons
- Too short for many applications
- May require special handling
LYD M4 Brass Hex Bolts, 25mm Length, 25 Pack
A balanced length for various projects. These bolts provide a secure hold and are easy to work with. Made from high-quality brass, they resist tarnishing. Some users mention that the hex head is slightly smaller than standard, but it still fits standard wrenches.
Pros
- Versatile length
- Good corrosion resistance
- Reasonable pack size
Cons
- Head size may be non-standard
- Not full thread? Actually full thread
LYD M4 Brass Hex Bolts, 8mm Length, 20 Pack
These are the shortest M4 brass bolts available, suited for joining thin sheets or mounting small components. They offer reliable performance in low-stress applications. Since they are so short, they require careful handling during installation.
Pros
- Ultra-short for tight spaces
- Good for thin materials
- Quality brass
Cons
- Limited application
- May strip if over-tightened
The lineup, side by side
| # | Model | Material | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | Hilitchi M4 Brass Hex Bolts, 20mm Length, 50 Pack | C36000 Brass | General purpose and electrical projects | 9.4 | Check price |
| 2 | LYD M4 Brass Hex Bolts, 16mm Length, 20 Pack | Brass | Compact assemblies and electronics | 9.1 | Check price |
| 3 | LYD M4 Brass Hex Bolts, 30mm Length, 10 Pack | Brass | Long reach applications | 8.8 | Check price |
| 4 | LYD M4 Brass Hex Bolts, 12mm Length, 50 Pack | Brass | High volume projects | 8.9 | Check price |
| 5 | LYD M4 Brass Hex Bolts, 10mm Length, 100 Pack | Brass | Precision work and small parts | 8.7 | Check price |
| 6 | LYD M4 Brass Hex Bolts, 25mm Length, 25 Pack | Brass | Medium-duty fastening | 8.5 | Check price |
| 7 | LYD M4 Brass Hex Bolts, 8mm Length, 20 Pack | Brass | Ultra-thin materials | 8.0 | Check price |
How to choose
Good to know
Are M4 brass hex bolts strong enough for structural applications?
Brass bolts are not as strong as steel, but they are suitable for light to medium-duty applications such as securing covers, brackets, and non-load-bearing joints. For high-stress or load-bearing uses, consider steel bolts.
Can I use M4 brass hex bolts outdoors?
Yes, brass has good corrosion resistance, making it suitable for outdoor use. However, in coastal or highly humid environments, brass may tarnish faster. Regular maintenance or a protective coating can help.
What is the thread pitch of M4 bolts?
The standard thread pitch for M4 bolts is 0.7mm. This is the distance between threads and is universal for metric M4 fasteners.
Do brass bolts conduct electricity?
Yes, brass is a good conductor of electricity, though not as conductive as pure copper. This makes brass bolts useful in electrical applications where grounding is needed.
How do I know which length to order?
Measure the thickness of the materials you are joining. The bolt should be long enough to pass through and extend beyond the nut by at least 2mm. Add about 5-6mm to your stack thickness to get the right length.
Are these bolts compatible with standard M4 nuts?
Yes, all M4 brass hex bolts have a standard M4x0.7 thread and will fit standard M4 nuts and tapped holes. Always check the thread pitch to ensure compatibility.
Can I cut brass bolts to a shorter length?
Yes, you can cut brass bolts with a hacksaw or rotary tool. After cutting, file the end to remove burrs and restore the thread with a die if needed.
Do brass bolts have any magnetic properties?
No, brass is not magnetic. This makes brass bolts ideal for applications where non-magnetic materials are required, such as in electronic equipment.
Will brass bolts rust?
Brass does not rust like steel, but it can corrode under certain conditions. It is resistant to moisture and many chemicals, but prolonged exposure to harsh environments may cause pitting. Regular cleaning helps.
What tools do I need to install M4 brass hex bolts?
You will need an M4 hex socket or wrench. A torque wrench is helpful for precise tightening. Always use the correct size to avoid stripping the head.
Our pick
After comparing these seven options, the Hilitchi M4 Brass Hex Bolts in 20mm length offer the best combination of quality, value, and versatility for most users. They are ideal for electrical and general DIY projects. For those needing shorter lengths for electronics, the LYD 12mm pack is a solid choice. Choose based on the specific length and quantity you need for your project.
