Black 304 Stainless Steel Carriage Bolts M5 M6 M8 – 20 Pack
Black 304 Stainless Steel Carriage Bolts M5 M6 M8 – 20 Pack
Black 304 Stainless Steel Carriage Bolts – M5, M6 & M8 | 20-Pack
Upgrade your builds with these premium 304 stainless steel carriage bolts finished in sleek matte black. Engineered for strength and longevity, these square-neck round-head bolts deliver a secure, rattle-free connection across a wide range of indoor and outdoor projects. Made in Mainland China.
Key Features
- Premium 304 Stainless Steel Construction: Excellent corrosion and rust resistance makes these bolts suitable for both interior and exterior use — from damp garages to outdoor decks.
- Classic Carriage Bolt Design: The dome-shaped round head and square neck work together to prevent spinning during tightening, delivering a firm, reliable connection every time.
- Available in M5, M6 & M8 Sizes: Multiple diameter options with lengths ranging from 8 mm up to 50 mm — easily matched with standard nuts and washers for a precise fit.
- Matte Black Finish: The sleek black coating gives a professional, modern look while adding an extra layer of surface protection.
- Fully Threaded Shaft: Provides maximum grip and holding power through wood, metal, and composite materials.
- Versatile Applications: Perfect for furniture assembly, deck construction, trailer builds, automotive bodywork, gate hardware, and general DIY projects.
- Quick & Easy Installation: Insert through a pre-drilled hole, seat the square neck in the material to prevent rotation, and tighten with a standard nut — no special tools required.
Specifications
| Material | 304 Stainless Steel (Carbon Steel base with black finish) |
| Grade | 304 Stainless Steel |
| Finish | Black |
| Thread Sizes | M5 / M6 / M8 |
| Length | 8 mm – 50 mm (variant dependent) |
| Head Style | Round (Dome) |
| Neck Style | Square (Anti-rotation) |
| Pack Quantity | 20 Carriage Bolts |
| Origin | Made in Mainland China |
What's in the Box
- 20 × Black Carriage Bolts (size per selected variant)
Note: Due to screen calibration differences, the actual product color may vary slightly from images shown. Measurement tolerance is ±1–3 mm.
You May Also Like
- 10-in-1 Multi Functional Bone Wrench Hex Socket Spanner – Portable Repair Hand Tool
- 16-in-1 Multi-Function Bike Repair Tool – Portable Folding Hex Wrench Set
- 48-Pc MIG Welding Nozzle & Tip Set – MB15 AK15 Torch
Learn more: OSHA on personal protective equipment
Frequently Asked Questions
Q: What is the difference between M5, M6, and M8 carriage bolts?
A: The "M" number refers to the metric thread diameter in millimetres. M5 bolts have a 5 mm shank diameter, M6 have a 6 mm shank, and M8 have an 8 mm shank. Larger diameters provide greater load-bearing capacity. Always match your bolt size to the corresponding metric nut and washer for the best fit.
Q: Can these black carriage bolts be used outdoors?
A: Yes. These bolts are made from 304 stainless steel with a black surface finish, offering solid corrosion and moisture resistance suitable for outdoor applications such as deck building, fencing, and gate hardware.
Q: How do I install carriage bolts so they don't spin?
A: Drill a hole sized to match the bolt's shank diameter, push the bolt through, and tap it gently so the square neck seats flush into the material (works best with wood or soft metal). The square neck grips the hole walls to prevent rotation while you tighten the nut from the other side with a standard wrench or socket.
Q: How many bolts are included in one pack?
A: Each pack contains 20 carriage bolts in your chosen size (M5, M6, or M8) and length variant. No nuts or washers are included.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.