Sturdy M5 Stainless Hex Bolts for Reliable Fixing
The Hilitchi 210-Piece M5 Stainless Steel Hex Bolt Assortment is the top pick for most users. It offers a broad range of lengths, making it versatile for various tasks. Its main advantage is the sheer value and convenience of having multiple sizes in one box. A limitation is that the included hex key may not fit perfectly, so using your own tool is wise.
M5 stainless steel hex bolts are essential for projects that need corrosion resistance and a clean look. They are common in automotive, marine, and outdoor furniture applications. Selecting the right set involves considering length variety, grade, and included washers or nuts.
Stainless steel offers better durability than zinc-plated steel, especially in moist environments. However, not all stainless is the same. Grade 304 is standard for general use, while grade 316 offers superior resistance to saltwater. Your choice depends on the environment and load requirements.
Our top picks
Hilitchi 210-Piece M5 Stainless Steel Hex Bolt Assortment
This kit includes 210 pieces of M5 hex bolts in six common lengths, from 8mm to 40mm. The bolts are made of 304 stainless steel for good corrosion resistance. Each length comes in a separate compartment in a sturdy plastic case. Users like the clear labeling and the convenience of having a variety on hand. Some note that the hex key provided is flimsy, so having your own is recommended.
Pros
- Large assortment covers common sizes
- Clear compartmentalized case
- Good corrosion resistance
Cons
- Included hex key is low quality
- Some bolts may have slightly rough threads
uxcell M5 x 20mm Hex Head Bolts, 304 Stainless Steel, 50 Pack
If you need a specific size, this 50-pack of M5 x 20mm bolts is a solid choice. They are made from 304 stainless steel and come with a clean finish. The threads are consistently cut, making installation smooth. Owners report using these for motorcycle parts and electronics enclosures with great success. The only downside is that you get only one length, so you may need to order other sizes separately.
Pros
- Excellent value per bolt
- Uniform quality
- Reliable threading
Cons
- Only one length available
- No washers or nuts included
M5 x 0.8 x 16mm Stainless Steel Hex Bolts with Nuts and Washers, 100 Sets
This set provides 100 complete sets of M5 x 16mm bolts, each paired with a nut and washer. The bolts are 304 stainless steel, and the included nuts are also stainless. It saves you from buying separate hardware. Users appreciate the convenience for projects that require a finished look. Some reviewers mention that the washer inner diameter is slightly small, so it may not fit over the bolt shank on every bolt.
Pros
- Everything you need in one box
- Consistent quality
- Good for small repairs
Cons
- Washers may be tight
- Limited to one length
Katsumoto 316 Stainless Steel M5 Hex Bolts, 10mm, 20 Pack
Made from marine-grade 316 stainless steel, these M5 x 10mm bolts offer superior corrosion resistance. They are ideal for saltwater environments or chemical exposure. The bolts have a smooth, rounded head and clean threads. While they are pricier than 304 options, the added durability justifies the cost for critical applications. Owners who used them on boat fittings report no rust after extended exposure.
Pros
- Top-grade corrosion resistance
- Smooth finish
- Strong and durable
Cons
- Higher price
- Short length only
Stainless Steel M5 Hex Bolts, 30mm Length, 25 Pack by Drill America
When you need a longer bolt, this 25-pack of M5 x 30mm hex bolts from Drill America fits the bill. They are manufactured from 304 stainless steel and feature a fully threaded shaft. The bolts are suitable for thicker materials or where you need extra grip. Some users find the head height to be a bit tall, but this does not affect performance.
Pros
- Long length for thick stacks
- Strong material
- Fully threaded
Cons
- May be too long for some jobs
- No storage case
M5 x 12mm Hex Bolts, 304 Stainless Steel, 100 Pack by Shiwal
These M5 x 12mm bolts from Shiwal are perfect for tight spaces and smaller assemblies. The 304 stainless steel construction provides good strength, and the 12mm length is ideal for mounting components. The threads are accurately cut, allowing smooth tightening. A few reviewers received a mix of partially threaded and fully threaded bolts, but they are still functional.
Pros
- Compact size for tight areas
- Large quantity
- Good finish
Cons
- Mixed threading types
- Not for heavy loads
Vaultz M5 Stainless Steel Hex Bolts, 8mm, 200 Pack
This bulk pack of 200 M5 x 8mm bolts is great for projects that use many short bolts. They are made from 304 stainless steel and come in a resealable bag. The short length is perfect for thin panels or brackets. While the price per bolt is low, the quality can be inconsistent, with some bolts having minor surface imperfections. Still, for non-critical uses, this is a cost-effective option.
Pros
- Very low cost per bolt
- Good for many fasteners
- Short length for thin materials
Cons
- Quality control issues
- No washers or nuts
How to pick the right one
How they stack up
| # | Model | Material | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | Hilitchi 210-Piece M5 Stainless Steel Hex Bolt Assortment | 304 Stainless Steel | Versatile kit with many lengths | 9.4 | Check price |
| 2 | uxcell M5 x 20mm Hex Head Bolts, 304 Stainless Steel, 50 Pack | 304 Stainless Steel | Single size bulk purchase | 9.0 | Check price |
| 3 | M5 x 0.8 x 16mm Stainless Steel Hex Bolts with Nuts and Washers, 100 Sets | Stainless Steel | Complete fastener sets | 8.8 | Check price |
| 4 | Katsumoto 316 Stainless Steel M5 Hex Bolts, 10mm, 20 Pack | 316 Stainless Steel | Marine and coastal use | 9.2 | Check price |
| 5 | Stainless Steel M5 Hex Bolts, 30mm Length, 25 Pack by Drill America | 304 Stainless Steel | Longer reach applications | 8.6 | Check price |
| 6 | M5 x 12mm Hex Bolts, 304 Stainless Steel, 100 Pack by Shiwal | 304 Stainless Steel | Small electronic and hobby projects | 8.4 | Check price |
| 7 | Vaultz M5 Stainless Steel Hex Bolts, 8mm, 200 Pack | 304 Stainless Steel | High volume short bolt needs | 8.2 | Check price |
Frequently asked questions
What does M5 mean on a hex bolt?
M5 refers to the nominal diameter of the bolt’s thread in millimeters, which is 5mm. The thread pitch is standard at 0.8mm for coarse threads.
What is the difference between 304 and 316 stainless steel?
304 stainless steel is an austenitic alloy with good corrosion resistance. 316 includes molybdenum, which enhances resistance to chlorides and acidic environments, making it suitable for marine applications.
Can I use M5 stainless steel hex bolts outdoors?
Yes, stainless steel bolts are suitable for outdoor use. Grade 304 will resist rust in most environments, but grade 316 is recommended for coastal areas or heavy rain.
Do I need to use a washer with these bolts?
Using a washer helps distribute load and prevents surface damage. Stainless steel washers are recommended to avoid galvanic corrosion with dissimilar metals.
What tools do I need to install an M5 hex bolt?
You will need a 5mm hex key (Allen wrench) or a socket wrench with an 8mm socket, since the hex head size is typically 8mm across flats.
How much torque should I apply to an M5 stainless steel bolt?
The recommended torque for a grade 304 stainless steel M5 bolt is about 5 to 6 Nm. Exceeding this can strip the threads or break the bolt.
Are these bolts fully threaded?
Most hex bolts are fully threaded, but some may have a partial thread. Check the product description. Fully threaded bolts provide more grip length.
Can I cut stainless steel bolts to a shorter length?
Yes, you can cut them with a hacksaw or angle grinder, but you will need to re-chase the threads with a die to clean them up.
Will stainless steel bolts rust?
Stainless steel is corrosion-resistant but not completely rust-proof. In harsh environments, they can develop surface stains, but they will not rust like carbon steel.
Can I reuse stainless steel hex bolts?
Yes, if they are not damaged. However, avoid galling by applying anti-seize lubricant when reusing them.
Our take
For most users, the Hilitchi 210-Piece Assortment offers the best balance of variety, quality, and value. If you need marine-grade performance, choose the Katsumoto 316 bolts. For bulk single-size needs, the uxcell 50-pack is a reliable pick.
