Views: 0 Author: Site Editor Publish Time: 2025-11-03 Origin: Site
In every solar mounting system, small components like bolts and fasteners play a crucial role in ensuring safety, strength, and long-term durability.
Among them, the stainless steel carriage bolt stands out as a reliable solar fastener that connects solar rails, clamps, and brackets securely.
With its round head and square neck design, it provides both mechanical stability and a clean appearance, making it an essential part of modern solar installations.
A carriage bolt, also called a round head square neck bolt, is a type of bolt fastener with a smooth, dome-shaped head and a square neck underneath.
The square neck prevents the bolt from turning when the nut is tightened, allowing for a firm connection between solar mounting components.
In solar applications, these bolts are often paired with nuts, washers, and clamps to form a durable and weatherproof connection between:
Solar rails and support beams
Ground screws or foundations
Module clamps and brackets
| Part | Function | Material |
|---|---|---|
| Round Head | Provides a smooth, corrosion-resistant surface | Stainless Steel 304 / 316 |
| Square Neck | Locks the bolt into the mounting hole or slot | Stainless Steel |
| Threaded Shank | Engages with nuts and washers for tightening | A2-70 / A4-80 Grade |
| Nut and Washer | Distribute load and ensure tightness | Stainless Steel or Aluminum |
This simple yet robust design ensures that each solar structure connection remains tight, vibration-resistant, and free from corrosion for decades.
The square neck design fits into the mounting rail slot or hole, preventing rotation during tightening.
Installers only need to tighten the nut — saving installation time and improving efficiency on-site.
Made of stainless steel 304 or 316, carriage bolts can withstand harsh outdoor environments such as coastal areas, deserts, or high-humidity regions.
These solar bolts are engineered to handle heavy mechanical loads, wind pressure, and vibration, ensuring that your solar array remains stable over time.
The rounded head design leaves a smooth surface, perfect for visible solar installations on rooftops or carports where aesthetics matter.
| Item | Description |
|---|---|
| Product Name | Stainless Steel Carriage Bolt for Solar Mounting |
| Material | Stainless Steel 304 / 316 / 316L |
| Standard | DIN 603, ISO 8677 |
| Size Range | M6 – M12 (custom available) |
| Length Range | 20mm – 120mm |
| Strength Grade | A2-70 / A4-80 |
| Surface Finish | Polished / Passivated |
| Application | Solar rail connection, bracket assembly, ground mount system |
| Solar Application | Function of Carriage Bolt |
|---|---|
| Roof Mounting Systems | Fixes rails to roof hooks and brackets |
| Ground Mount Systems | Connects support beams to ground screws |
| Solar Carports | Joins steel beams and solar frames |
| Floating Solar Systems | Fastens solar module frames and floating platforms |
| Adjustable Mounting Kits | Works with nuts, washers, and clamps for angle adjustments |
In all of these systems, stainless steel carriage bolts serve as critical solar fasteners that maintain alignment, absorb stress, and resist loosening.
| Feature | Benefit |
|---|---|
| Anti-Loosening Design | Square neck prevents rotation during tightening |
| Long-Term Corrosion Protection | 316 stainless steel performs well in outdoor and coastal conditions |
| High Tensile Strength | Withstands wind and snow loads |
| Universal Compatibility | Fits most solar mounting rails and accessories |
| Low Maintenance | Once installed, requires little to no upkeep |
Using high-quality stainless steel bolts in your solar bracket system ensures 25+ years of reliability — matching the lifespan of solar panels.
| Material | Grade | Properties | Application |
|---|---|---|---|
| Stainless Steel 304 (A2-70) | Standard strength | Corrosion resistant for general outdoor use | Residential and commercial rooftops |
| Stainless Steel 316 (A4-80) | High strength, molybdenum added | Excellent corrosion resistance | Coastal or industrial zones |
| 316L | Low carbon stainless steel | Improved weldability | Solar carports and large-scale projects |
Align the rail and bracket holes.
Insert the stainless steel carriage bolt — the square neck fits snugly into the rail slot.
Place a flat washer and spring washer on the threaded end.
Tighten the nut with a wrench while the bolt head stays fixed.
Check alignment to ensure even pressure and secure fastening.
Tip: Pair with anti-loosening nuts or lock washers for areas exposed to vibration or strong winds.
| Feature | Carriage Bolt | Hex Bolt |
|---|---|---|
| Head Type | Round head | Hexagonal head |
| Anti-Rotation | Yes (square neck locks into place) | No |
| Tool Access Needed | Only one side | Both sides |
| Aesthetic | Smooth, clean finish | Industrial appearance |
| Ideal Use | Solar mounting rails, visible structures | Structural steel frames |
Carriage bolts are especially suitable for solar mounting structures where both functionality and appearance are important.
Always use matching stainless steel nuts and washers to prevent galvanic corrosion.
Avoid mixing carbon steel with stainless steel fasteners.
Regularly inspect solar structures for bolt tightness after extreme weather events.
Use A4-80 stainless steel carriage bolts for coastal or humid climates.
The stainless steel carriage bolt is a small but essential component in any solar mounting system.
Its square neck anti-rotation design, high corrosion resistance, and smooth finish make it the perfect solar fastener for connecting rails, brackets, and supports.
By choosing the right stainless steel bolt grade, you can ensure long-term performance, safety, and stability — keeping your solar energy system efficient and secure for decades.
1. Why use carriage bolts in solar mounting systems?
Because their square neck prevents rotation during tightening, providing a stable and secure connection between solar rails and brackets.
2. Which material is best for solar fasteners?
Stainless steel 316 (A4-80) offers the best corrosion resistance for outdoor solar installations.
3. What sizes are common in solar systems?
Typically M6, M8, and M10 carriage bolts are used depending on rail size and structure load.
4. Can carriage bolts be used for ground-mounted solar systems?
Yes, they are widely used to fasten ground screws, base plates, and support beams.
5. How long do stainless steel carriage bolts last?
They can last over 25 years, matching the lifespan of solar panels and other mounting hardware.
