1/4 in x 6 in Carriage Bolt Kit (100 Pack) - Hot Dip Galvanized

Our review of this 1/4 in x 6 in carriage bolt kit finds it aimed squarely at DIYers and contractors who need a large quantity of corrosion-resistant fasteners for exterior timber projects. The single biggest reason to buy is the complete kit of 100 Grade 307A carriage bolts plus 100 USS flat washers and 100 hex nuts, all hot dip galvanized to withstand outdoor exposure and use in ACQ treated lumber. The flat head produces a semi-flush finish that suits decks, pergolas and gazebos where a low-profile appearance and durability are priorities.

Key Features

• Kit completeness: The pack contains 100 carriage bolts, 100 USS thick washers and 100 hex nuts so you can fasten many connections without buying components separately.
• Hot dip galvanized coating: Provides superior corrosion resistance for exterior use and compatibility with ACQ treated lumber.
• Semi-flush flat head: The flat head with 0.578 in diameter offers a lower profile finish that reduces snagging on decks and outdoor structures.
• Standard nut and wrench size: The 1/4 in-20 hex nuts fit a 7/16 in wrench for simple installation with common tools.
• Meets industry standards: Conformance to ASME and ASTM specifications gives confidence in material and dimensional consistency for structural uses.

Who It's For

This kit is best for homeowners, landscapers and builders who assemble multiple outdoor structures and need a bulk supply of matching hardware that resists corrosion. It suits projects like decking, pergolas, gazebos and heavy timber connections where semi-flush carriage bolt heads are preferred for appearance and safety.

It is less appropriate for precision metalwork or applications that require specialty bolt grades or non-galvanized finishes; buyers needing smaller quantities or metric fasteners should look elsewhere.

Pros & Cons

Pros

• High value quantity: 100 bolts, washers and nuts save time and multiple purchases.
• Durable hot dip galvanized finish offers long-term corrosion resistance outdoors.
• Designed for ACQ lumber use, minimizing risk of accelerated corrosion in treated wood.

Cons

• The kit is limited to 1/4 in diameter and 6 in length, so different sizes require separate purchases.

Specifications

Diameter	1/4 in
Length	6 in
Head diameter	0.578 in
Nut thread	1/4 in-20
Nut wrench size	7/16 in
Washer outside diameter	47/64 in
Components	100 carriage bolts, 100 USS washers, 100 hex nuts

Our Verdict

This carriage bolt kit is a practical, cost-effective option for anyone building or repairing outdoor wood structures who needs a bulk supply of matched fasteners with reliable corrosion protection. The hot dip galvanized finish and standards compliance make it a sensible choice for decking and pergola projects, offering good long-term value for common exterior fastening needs.

Frequently Asked Questions

Are these bolts suitable for treated lumber?
Yes, the hot dip galvanized coating and listed suitability mean they are appropriate for use with ACQ treated lumber.

What tools are required to install them?
The hex nuts use a 7/16 in wrench, and standard sockets or wrenches sized to that will work for installation.

Does the kit include washers and nuts?
Yes, the kit includes 100 USS thick washers and 100 Grade 2/A hex nuts along with 100 carriage bolts.