Answering the buyer’s search: these brake backing plate bolt kits and related hardware are chosen for reliability, proper fit, and easy compatibility with common trailer brake assemblies. The top picks are suited for different trailer axle ratings (10K, 12K, 15K) and backing plate patterns, helping buyers select the right hardware with confidence. This guide highlights who each product is best for, why it was chosen, and practical cautions to consider before buying. A quick comparison table follows to help you decide at a glance.
| Product | Best For | Key Benefit |
|---|---|---|
| Hexzian 7/16″-20 x 1-3/4″ Kit | 12-1/4″ backing plates on 10K/12K/15K axles | Complete mounting hardware with OEM-style bolts |
| Inline Tube 16pc Replacement Set | GM-era backing plate bolts & lock nuts | Exact reproduction parts for classic GM setups |
| Inline Tube 2pc Front Disc Backing Plate Bolts | Front disc brake backing plates | Caliper bracket to spindle mounting compatibility |
| Aizhuer 2-Pack Flange | 3-1/8″ hole backing plates on 4-bolt patterns | Durable flange design for specific axle sizes |
| BBMTA 2-Pack 2.27″ Flange | 2,000–3,500 lb axles with 4-bolt square brackets | Weld-on mounting option for certain builds |
Hexzian Brake Backing Plate Mounting Kit
The Hexzian kit is designed for 12-1/4″ trailer brake backing plates with a 7-hole mounting pattern and is compatible with 10K, 12K, and 15K trailer axles. It includes seven hex cap screws, seven split lock washers, and seven hex nuts—providing a complete mounting solution that ensures strong clamping and reliable alignment. This kit is best for buyers who want a ready-to-install set that matches OEM-style specifications. A potential limitation is that it is tailored to a specific backing plate size, so verify your plate’s pattern before purchasing.
Best for: Trailer owners upgrading or replacing mounting hardware on 12-1/4″ backing plates with 7-hole patterns. Choose this if you want a complete, OEM-style kit with standard 7/16″-20 fasteners for robust mounting.
Inline Tube 16pc GM Backing Plate Bolts & Lock Nuts
This Inline Tube set is positioned as exact reproduction hardware for 1964–1977 A-Body, 1967–1972 GM Front Disc, and related GM backings. It includes bolts and lock nuts designed to match original dimensions, making it a strong choice for restoring classic trailers or vehicles needing faithful reproduction components. Best for: Restorations of GM-era backing plates where authentic hardware matters. Limitation: It is not marketed as a broad universal kit, so confirm your model’s compatibility before buying.
Inline Tube Front Disc Backing Plate Bolts (2pc)
These Inline Tube bolts are intended for GM front disc backing plates and caliper bracket-to-spindle mounting nuts on single-piston caliper setups. The two-piece configuration can be advantageous for owners replacing specific hardware on older front-disc assemblies. Best for: Maintenance or rebuild tasks where the front disc backing plate mounting hardware is included in the kit. Caution: Verify the bolt length and thread pitch to ensure proper clamping force and spacing on your spindle.
Aizhuer 2-Pack Backing Plate Flange
The Aizhuer flange is designed for trailer backing plates with a 3-1/8″ inner hole diameter and a 4-1/2″ width. It uses a 3-1/8″ center hole and supports 3/8″ bolts. This product suits buyers with 3-1/8″ inner hole requirements and four- or five-bolt configurations. Best for: Replacing a flange on a specific trailer axle with this exact inner diameter and bolt size. Limitation: Data notes the shaft diameter and hole size; ensure your mounting hardware matches before purchase.
BBMTA 2-Pack 2.27″ Backing Plate Flange
The BBMTA 2.27″ flange is designed for 4-hole bolt square brackets used on 2000 lb and 3500 lb axles. It is a weld-on component, measuring 3-3/4″ wide with a 1/4″ thickness. Best for: Weld-on installations requiring a square 2.27″ flange with a 4-bolt pattern. Caution: This part must be welded on, so it is not a simple bolt-on replacement for all trailers.
BBMTA Weld-On 1.64″ Flange Set
BBMTA’s 1.64″ flange is intended for a 4-hole bolt square bracket and weld-on applications on 2,000 lb to 3,500 lb axles. It provides a robust mounting interface with a 4-hole bolt pattern. Best for: Weld-on mounting projects requiring a larger center hole with a square bracket. Limitation: It requires welding, which may not suit every trailer setup.
Buying Guide
Key considerations when choosing brake backing plate bolts and related hardware:
- Backing Plate Size and Pattern: Confirm diameter, hole count, and bolt pattern before selecting hardware. Mismatched patterns lead to poor seating and leaks.
- Axle Capacity: Choose parts compatible with 10K, 12K, or 15K axles as appropriate for your trailer’s gross vehicle weight rating (GVWR).
- Mounting Style: Bolt-on versus weld-on options affect installation work and required tools. Weld-on parts require fabrication and welding skills or professional service.
- Material and Finish: Look for corrosion-resistant finishes suitable for trailers used in varied climates.
- Hardware Completeness: Complete kits with bolts, nuts, and washers save time and ensure balanced clamping.
Frequently Asked Questions
- What size bolts are common for trailer brake backing plates? Typical size is 7/16″-20 in many 12-1/4″ backing plates, but verify your exact pattern before ordering.
- Are weld-on backing plate flanges more durable than bolt-on? Weld-on options provide strong, permanent mounting but require welding, while bolt-on gives easier removal and replacement.
- Can I mix parts from different brands? It’s best to match backing plate size and bolt pattern for proper fit and clamping.
- What signals a compatible kit for 10K, 12K, or 15K axles? Check the kit’s documentation or product features for axle class compatibility.
- Do these kits include all mounting hardware? Some kits are complete, while others require additional nuts or washers; verify contents in the product features.
- How do I know if I need a flange versus straight bolts? If your trailer uses specific inner hole diameters or a particular bolt pattern, choose a matching flange or bolt set accordingly.