1/4 in x 3 in Carriage Bolt Kit (100 Pack) - Hot Dip Galvanized

Our review of this 1/4 in x 3 in carriage bolt kit finds it best suited for builders and DIYers who need a reliable, corrosion-resistant fastener pack for outdoor projects. The single biggest reason to buy is the hot dip galvanized coating combined with a complete hardware set: 100 Grade 307A carriage bolts, 100 USS flat washers and 100 hex nuts. That combination removes the usual hassle of sourcing matching pieces, and the flat head design gives a semi-flush finish that works well on decks, pergolas and other heavy duty timber applications.

Key Features

• Complete kit: Includes 100 carriage bolts, 100 USS flat washers and 100 hex nuts so projects can proceed without hunting down matching parts.
• Hot dip galvanized coating: Provides superior corrosion resistance for exterior use and compatibility with ACQ treated lumber.
• Flat head design: The semi-flush flat head reduces snagging and yields a cleaner look on deck and pergola surfaces.
• Standard fit: The 1/4 in-20 nut thread and 7/16 in wrench size make these bolts easy to use with common tools.
• Meets industry specs: Manufactured to meet or exceed relevant ASME and ASTM standards for consistent performance.

Who It's For

This kit is aimed at contractors, deck builders and serious DIYers who install outdoor structures and need a bulk supply of matched carriage bolts and hardware. The hot dip galvanized finish and Grade 307A bolts make it appropriate for use with ACQ treated lumber and other exterior applications where corrosion resistance matters.

Hobbyists with small one-off projects might find the 100-piece quantity more than required, and those needing larger diameters or specialty head styles should look for alternate fasteners better matched to those specific needs.

Pros & Cons

Pros

• Complete 100-piece kit removes the need to source washers and nuts separately, saving time.
• Hot dip galvanized finish offers strong corrosion protection for outdoor and ACQ lumber projects.
• Flat head carriage bolt provides a semi-flush finish that improves appearance and reduces tripping or snag points.

Cons

• Pack size is large for casual users with only a few fasteners needed.
• Limited to 1/4 in diameter and 3 in length, so not suitable for thicker assemblies.

Specifications

Our Verdict

This 1/4 in x 3 in carriage bolt kit is a practical, cost-effective choice for those building decks, gazebos, pergolas or other outdoor wood structures. The matched hardware and hot dip galvanized coating deliver reliable corrosion resistance and convenience, making the kit good value for contractors and DIYers who need a bulk supply of standardized fasteners.

Frequently Asked Questions

Are these bolts suitable for pressure-treated lumber?
Yes, the hot dip galvanized coating is suitable for use with ACQ treated lumber and other exterior applications.

What tools are required to install these bolts?
The nuts require a 7/16 in wrench and the carriage bolts seat with a standard hammer or mallet; common hand tools are sufficient.

Does the kit include washers and nuts?
Yes, the kit includes 100 USS thick flat washers and 100 Grade 2/A hex nuts matched to the 1/4 in-20 thread.