Carriage Bolt & Barrel Torx Nut Kit — 5/16-18 x 1"
A compact 2-piece trailer hardware kit for applications that need a 5/16-18 carriage bolt with a low-profile flanged barrel Torx nut. Commonly used on enclosed trailer door hardware, bar-lock assemblies, latch plates, hinges, hasps, and toolbox hardware where measurements match.
Key Measurements & Specs
| Specification | Detail |
|---|---|
| Part Number / SKU | 516C1CB5Z-KIT |
| Product Type | Carriage bolt and flanged barrel Torx nut kit |
| Thread Size | 5/16-18 coarse thread |
| Bolt Size | 5/16-18 x 1" |
| Material / Finish | Grade 5 steel, zinc plated |
| Quantity Included | 1 carriage bolt and 1 barrel Torx nut |
Fitment / Application
| Category | Details |
|---|---|
| Trailer Systems | Enclosed cargo trailers, utility trailers, motorcycle haulers, toolbox and equipment trailer hardware |
| Common Locations | Bar-lock rods, cam latch plates, swing-door hinges, hasps, latch housings, and toolbox hinges |
| Fitment Method | Verify 5/16-18 thread, 1" bolt length, mounting thickness, barrel depth, and clearance |
| Important Note | Application reference only; compare to existing hardware before ordering |
Top Features
| Feature | Buyer Benefit |
|---|---|
| Square-Neck Bolt | Helps keep the bolt from spinning while tightening |
| Flanged Barrel Nut | Creates a cleaner, lower-profile interior finish |
| T45 / Allen Drive | Installs with T45 Torx or 7/32" Allen tooling |
| Solid-End Nut | Designed for finished-depth applications; bolt does not pass through |
Overview
This 5/16-18 x 1" carriage bolt and flanged barrel Torx nut kit is built for secure trailer hardware mounting where a smooth carriage bolt head and low-profile interior barrel nut are preferred. It is a practical replacement kit for matching enclosed trailer latch hardware, hinge plates, hasps, lock rods, and toolbox hardware.
R&P Service Insight
When replacing specialty trailer fasteners, the thread and length are only part of the match. Barrel diameter, barrel length, panel thickness, and tool access should also be confirmed before installation.
- Thread Match: Confirm 5/16-18 coarse thread.
- Depth Check: This kit uses a solid-end barrel nut; bolt pass-through is not available.
- Tooling: The nut accepts T45 Torx or 7/32" Allen tooling.
R&P Knowledge Hub
Compatibility: Compatible with listed trailer hardware applications only where the measurements and mounting depth match.
System Fit: Commonly used on enclosed trailer door hardware, cam latch plates, bar-lock rods, hinges, hasps, latch housings, and toolbox hardware.
Installation Notes: Verify bolt length, barrel nut length, panel thickness, and drive clearance before tightening.
Performance Insight: The square-neck carriage bolt helps resist spinning while the flanged barrel nut provides a cleaner interior-side finish than a standard exposed nut.
Brand & Fitment Note
Selling Brand: R&P Carriages hardware kit
Application Reference: Trailer and hardware references are provided for fitment guidance only.
What This Means: This listing is for one curated R&P Carriages hardware kit, not a guaranteed OEM-branded item unless specifically stated.
Before Ordering: Verify thread size, bolt length, barrel diameter, barrel length, drive type, mounting thickness, and included components.
R&P Repair Insight
Specialty trailer door fasteners are often chosen for clearance, security, and appearance. Always compare the original bolt and nut to the specifications below before replacing.
- Check Bolt Length: Confirm the 1" bolt length works with your panel and hardware stack-up.
- Check Barrel Size: Barrel nut length is .597" and barrel diameter is .430".
- Check Pass-Through: This is a solid-end nut and does not allow the bolt to pass through.
Features
5/16-18 Coarse Thread
Matches applications that require a 5/16-18 carriage bolt and matching barrel nut.
Grade 5 Zinc-Plated Steel
Provides a practical strength and finish combination for trailer service hardware.
Low-Profile Interior Finish
The flanged barrel nut helps reduce exposed hardware on the inside face of the installation.
Trailer Hardware Ready
Commonly used for latch plates, hasps, hinges, bar-lock hardware, and toolbox mounting points.
Included Components
| Quantity | Item |
|---|---|
| 1 | 5/16-18 x 1" Grade 5 zinc carriage bolt, square neck |
| 1 | 5/16-18 flanged barrel Torx nut, .597" length, .430" barrel diameter |
| Not Included | Additional bolts, nuts, brackets, hinges, latches, or installation tools |
