1/2"-13 x 3-1/2" Grade 8 Carriage Bolts (4-Pack) – Heavy-Duty Coarse Thread Bolts – Round Head Square Neck SAE J429 3.5" Black Finish
Product details
| Management number | 250201375 | Release Date | 2026/09/17 | List Price | US$7.50 | Model Number | 250201375 | ||
|---|---|---|---|---|---|---|---|---|---|
| Category | |||||||||
These 1/2"-13 x 3-1/2" (3.5") long Grade 8 (G8) Carriage Bolts are engineered for applications where strength, reliability, and vibration resistance matter most. Black finish. Each pack includes 4 Grade 8 carriage bolts. Designed for use in automotive repairs, trailer builds, agricultural equipment, shop machinery, and structural assemblies, this product eliminates the need to source parts separately—saving time while ensuring proper fit and performance. Whether you’re a professional mechanic, fabricator, or serious DIYer, this fastener kit delivers the confidence of industrial-grade hardware in a convenient, ready-to-use package.
- Complete 4-packs: Includes 4 Grade 8 carriage bolts. Bolts 1/2" diameter x 3-1/2" long.
- Smooth round head with square neck – Features a domed, low-profile head and square shoulder that locks into wood or other materials to help prevent bolt rotation during tightening, allowing installation with a single wrench.
- Grade 8 Strength for Demanding Jobs: High-tensile SAE J429 Grade 8 bolts deliver superior load capacity and shear strength, making this ideal for automotive, trailer, machinery, and structural applications. Threads are made to the requirements of ASME B1.1. ASME B18.5 Dimensional Requirements. SAE J429 Material and Strength Level. ASTM F788 Surface Discontinuities. ASME B18.18 Inspection and Quality Assurance.
- Precision-Matched Components: All fasteners are 1/2"-13 UNC for reliable fit and consistent clamping force across every assembly — no mismatched hardware, no guesswork. Black finish.
- Built for Pros & Serious DIYers: Whether you’re repairing equipment, building fixtures, or assembling heavy components, this kit delivers industrial-grade reliability in a compact, easy-to-store format.
| ASIN | B0H8RNRHDG |
|---|---|
| Brand | Quantum Forge |
| Color | Black |
| Model | QFG37208-FBA |
| Set Name | 1/2" x 3-1/2" Bolts Only |
| Head Type | Round |
| Size Name | 1/2" x 3-1/2" Bolts Only |
| Metal Type | Alloy Steel |
| Unit Count | 4 Count |
| Item Length | 3.5 inches |
| Part Number | QFG37208-FBA |
| Thread Size | 1/2"-13 |
| Thread Type | Unc |
| Finish Types | Black |
| Manufacturer | Quantum Forge |
| Thread Class | 2A |
| Thread Style | Right Hand |
| Fastener Size | 1/2"-13 |
| Fastener Type | Carriage Bolt |
| Item Diameter | 0.38 inches |
| Item Hardness | Grade 8 |
| Material Type | Alloy Steel |
| Exterior Finish | Black |
| Item Dimensions | 3.5 x 0.75 x 0.75 inches |
| Number Of Items | 4 |
| Thread Coverage | Fully Threaded |
| Number of Pieces | 4 |
| Outside Diameter | 0.38 inches |
| Screw Head Style | Round |
| Manufacturer Grade | Grade 8 |
| Maximum Shear Strength | 150,000 psi min tensile |
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