3/8 in x 7 in Carriage Bolt Kit (50 Pack) - Galvanized for Exterior

In this review of the 3/8 in x 7 in carriage bolt kit, the bottom line is simple: this set is aimed at DIYers and contractors who need reliable, corrosion-resistant fasteners for outdoor wood projects. The biggest reason to buy is the hot dip galvanized coating on Grade 307A carriage bolts, which offers far better corrosion protection than plain steel and keeps connections secure on decks, pergolas, fences and gazebos. The kit's inclusion of USS flat washers and hex nuts also makes it a practical choice for jobs that require semi-flush carriage bolt heads and complete hardware packages.

Key Features

• Complete kit: Includes 50 carriage bolts, 50 USS thick washers and 50 hex nuts so a full project run can be completed without sourcing extra parts.
• Durable coating: Hot dip galvanized finish provides superior corrosion resistance for exterior use and long-term exposure to the elements.
• Correct dimensions: 3/8 in diameter and 7 in length suit common heavy timber and decking connections for deep, secure engagement.
• Semi-flush head: The flat carriage head gives a semi-flush finish that reduces snags and looks tidy on decking and pergola rails.
• Matched hardware: Grade 307A bolts paired with grade 2 hex nuts and USS flat washers ensure compatible strength and fit for typical wood construction tasks.

Who It's For

This kit is ideal for homeowners, deck builders and fence installers who need a bulk supply of heavy-duty carriage bolts for exterior woodworking projects. The 7 in length is well suited to thick posts, multi-layer beam assemblies and situations where long bolt engagement is required for strength and stability.

Those who should look elsewhere include users needing stainless steel fasteners for marine or highly corrosive environments, or anyone requiring non-standard bolt head styles or metric dimensions; this kit is specifically imperial-sized, hot dip galvanized, and designed for common exterior wood applications.

Pros & Cons

Pros

• Hot dip galvanized coating gives reliable corrosion resistance for outdoor use.
• Packaged as a complete set of 50 bolts, washers and nuts, saving time sourcing parts.
• Flat carriage head produces a neat, semi-flush finish suited to decks and pergolas.
• Grade 307A carriage bolts paired with grade 2 nuts provide appropriate strength for heavy wood connections.

Cons

• USS washers received mixed feedback from some users, so washer thickness may not meet every specialized preference.
• Not stainless steel, so in extremely corrosive or coastal conditions stainless hardware may be a better choice.

Specifications

Diameter	3/8 in
Length	7 in
Head diameter	0.813 in
Washer outside diameter	1 in
Nut wrench size	9/16 in
Contents	50 carriage bolts, 50 USS flat washers, 50 hex nuts
Finish and grade	Hot dip galvanized, Grade 307A bolts, grade 2 nuts

Our Verdict

The 3/8 in x 7 in carriage bolt kit is a practical, good-value choice for anyone building or repairing exterior wooden structures. With hot dip galvanized Grade 307A carriage bolts and matching nuts and USS washers, it delivers durability and convenience for decks, pergolas and fences; those needing stainless or metric hardware should choose an alternative.

Frequently Asked Questions

Are these bolts suitable for outdoor use?
Yes, the hot dip galvanized coating provides superior corrosion resistance intended for exterior applications.

Do the nuts and washers come in this kit?
Yes, the kit includes 50 USS thick washers and 50 hex nuts matched to the 50 carriage bolts.

What size wrench is needed?
The hex nuts require a 9/16 in wrench for tightening.