1/4" x 3/4" Zinc Plated Flat Head Carriage Bolts & Lock Nuts with Knurled Neck, 25 Sets, Track Hardware Replacement for Garage Doors, Curved Rails & Extension Ladders
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- Precision Fit & Anti-Spin Design: Engineered with a unique knurled neck that securely grips the hardware hole, preventing the bolt from spinning during installation. This flat head design ensures a flush, snag-free finish on your garage door tracks or ladder rungs.
- Universal Garage & Ladder Compatibility: The perfect 1/4-20 x 3/4" replacement kit for vertical and curved garage door tracks. Also widely used for repairing extension ladder hinges and rails. A versatile hardware essential for both homeowners and professional garage door technicians.
- Corrosion-Resistant Zinc Finish: Manufactured from high-strength steel with a premium zinc plating. Designed to resist rust and corrosion in humid garage environments, ensuring long-lasting structural integrity and safety for your overhead door systems.
- Secure Self-Locking System: Each set includes a matching lock nut designed to stay tight under constant vibration and tension. Replace your worn-out, loose hardware with this professional-grade kit to restore smooth, quiet operation to your door tracks.
- Bulk 25-Set Project Value: Comes in a convenient 25-piece bulk pack, providing enough hardware for a full track overhaul or multiple ladder repairs. A must-have for your home maintenance kit to handle emergency repairs quickly and efficiently.
Estimated shipping
Select a product to estimate shipping.Why Choose Our Bolts?
Anti-Loosening Tech: The knurled neck and ribbed design create a “locked-in” effect, even in high-vibration environments.
Corrosion Resistance: Zinc plating shields against moisture, chemicals, and UV exposure.
25-Pack Convenience: Stock up for multiple projects—no mid-job hardware runs!
Why do garage door vertical and curved tracks require a "Flat Head" bolt? Can I use a standard carriage bolt?
Standard carriage bolts protrude into tracks, causing rollers to bump, wear, or derail. Our Flat Head track bolts sit perfectly flush with the interior steel track wall, providing a seamless, quiet pathway for the rollers.
What is the purpose of the "Knurled/Ribbed Neck" under the flat head?
Tight corners make holding a bolt inside tracks impossible. Our Ribbed Neck features teeth that bite into bracket slots to lock the bolt, allowing single-wrench tightening from the outside and preventing spin-out.
What are the exact dimensions of these bolts? Will they fit my standard residential tracks?
Standard specs:
1. Thread Size: 1/4"-20 coarse thread.
2. Length: 3/4" (19mm) under-head length, the universal size for splicing residential vertical and curved track joints.
3. Nut Drive Size: 7/16-inch Hex Serrated Flange Lock Nut.
Why do you provide "Serrated Flange Lock Nuts" instead of standard hex nuts?
Shaking loosens plain nuts, causing track collapse. Our kit includes Serrated Flange Lock Nuts. The serrated teeth grip the bracket, acting as integrated lock washers that stay tight under severe, long-term vibration.
Can these flat head bolts be used to repair Werner or Louisville extension ladders?
Yes! Used for extension ladders (Werner, Louisville, Keller) to secure locks/shoes. Flat heads sit flush so sliding ladder sections pass smoothly without catching, scratching, or jamming, unlike protruding standard bolts.
Product details
| Main Specification | |
|---|---|
| Manufacturer | Eteng Metals |
| Unit Count | 25 Count |
| Exterior Finish | Zinc |
| Metal Type | Alloy Steel |
| Head Style | Flat |
| Manufacturer Grade | Grade 2 |
| Thread Coverage | Partially Threaded |
| Outside Diameter | 0.25 Inches |
| Brand | eturnloger |
| Head Type | Flat |
| Number of Items | 25 |
| Fastener Type | Carriage Bolt |
| Included Components | bolts and nuts |
| Item Diameter | 0.25 Inches |
| Number of Pieces | 25 |
| Fastener Size | 1/4 inch |
| Thread Size | 1/4"-20 |
| Material | Alloy Steel |
| Colour | Silver |
| Thread Type | Unc |
| Product information | |
| Set Name | 25-Piece Zinc Plated Flat Head Carriage Bolt and Lock Nut Set |
| Technical Details | |
| Material | Alloy Steel |
| Model | CB25USA |
| Thread Size | 1/4"-20 |
| Material Type | Alloy Steel |
| Brand | Eturnloger |
| Thread Style | Left Hand |
| Compatible groove diameter | 0.25 Inches |
| Item Hardness | Grade 5 |
| Item details | |
| Item Type Name | Carriage Bolt and Nuts |
| Style | |
| Finish Types | Silver |
| Measurements | |
| Item Dimensions | 0.8 x 0.43 x 0.43 inches |
| Others | |
| Product Type | Carriage Bolt and Nuts |
| Grade Rating | Class 5 |
| Size Name | 1/4 in |
| Screw Head Style | Flat |