Tools & Home Improvement

The Best Carriage Bolts

1 min read WeKompare Editorial Team Products verified: July 16, 2026 10 products compared

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Carriage bolts are essential fasteners for creating strong, secure connections in wood and metal projects. Their unique design prevents them from turning when tightened, ensuring a stable and reliable joint. Choosing the right carriage bolt is crucial for the longevity and safety of your construction or repair work.

No. 1
1/2' x 8' (25 Pack) Galvanized Carriage Bolt Kit Grade 307A Includes 1/2' USS Flat Washers (25 pcs) and...
1/2" x 8" (25 Pack) Galvanized Carriage Bolt Kit Grade 307A Includes 1/2" USS Flat Washers (25 pcs) and...
  • Diameter: 1/2" | Length: 8" | Head diameter: 1.062" | Nut diameter: 1/2" | Nut wrench size: 3/4" | Washer outside diameter: 1-3/8"
  • Kit includes 25 Grade 307A carriage bolts, 25 USS thick washers, 25 Grade 2/A hex nuts
  • Hot dip galvanized coating for superior corrosion resistance, Suitable for use in ACQ treaded lumber
  • The flat head provides a semi-flush finish and is perfect for decks, gazebos, pergolas, and other heavy duty applications
  • Meets or Exceeds: ASME B18.5, ASTM A307, ASME B18.2.2, ASTM A563, ASME B18.21.1, ASTM F2329
$68.87
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No. 2
3/8' x 3-1/2' (50 Pack) Galvanized Carriage Bolt Kit, Grade 307A, Hot Dip Galvanized for Exterior Use by...
3/8" x 3-1/2" (50 Pack) Galvanized Carriage Bolt Kit, Grade 307A, Hot Dip Galvanized for Exterior Use by...
  • Diameter: 3/8" | Length: 3-1/2" | Head diameter: 0.813" | Nut diameter: 3/8" | Nut wrench size: 9/16" | Washer outside diameter: 1"
  • Kit includes 50 carriage bolts, 50 USS thick washers, 50 hex nuts
  • Hot dip galvanized coating for superior corrosion resistance
  • Grade 307A carriage bolts, grade 2 hex nuts, and USS flat washers
  • The flat head provides a semi-flush finish and is perfect for decks, gazebos, pergolas, and other heavy duty applications
$46.61
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No. 3
VGBUY 3/8-16 x 2-1/2' Carriage Bolts Screws 6 Sets, 304 Stainless Steel 18-8, Round Head Square Neck, Carriage...
VGBUY 3/8-16 x 2-1/2" Carriage Bolts Screws 6 Sets, 304 Stainless Steel 18-8, Round Head Square Neck, Carriage...
  • Strong Carriage Bolts: Carriage bolt is dome head bolt fastener with a locking neck style, which prevents turning when the nut it tightened or removed. Can be used in wood, metal applications
  • Stainless Carriage Bolts: Our 304 stainless steel carriage bolts 3/8 are of excellent corrosion resistance and durability. These carriage bolts 3/8 x 2-1/2 are ideal for both indoor and outdoor use
  • Well Made Carriage Bolts 2-1/2 Inch: All of the stainless steel bolts and hex nuts and flat washers are well manufactured with no burs, smooth-symmetrical head, precise and clean threads
  • Complete Bolts Nuts Washers Kit: You will get 6pcs 3/8-16 x 2-1/2" carriage bolts, 6pcs 3/8-16 hex nuts, 6pcs 3/8" ID flat washers in one package. Standard size, the bolt conforms to ASME B 18.5
  • Versatile: Carriage bolts aren't just for carriages, these bolts can be used on wood projects, timber frame shed build, trailer deck boards, deck project, outdoor bench seat rebuild, etc.
$9.49
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No. 4
EASTPUK 60Pcs 1/4-20 Carriage Bolts Assortment Kit with Nuts and Washers, 304 Stainless Steel Round Head...
EASTPUK 60Pcs 1/4-20 Carriage Bolts Assortment Kit with Nuts and Washers, 304 Stainless Steel Round Head...
  • PRODUCT SIZE - Thread Diameter: 1/4", Length: 5/8, 3/4, 1-1/4, 1-1/2, 2", Thread Pitch: 0.05", Head Diameter: 0.56“, Head Height: 0.15”. Ideal for wood projects, timber frame shed, trailer deck boards, deck construction, outdoor bench rebuild.
  • SECURE AND RELIABLE - The round head and square neck design of carriage bolts ensure a secure fit in square holes. When used with 1/4 hex nuts and flat washers, they provide reliable and stable fastening. Carriage bolts have a dome head and locking neck...
  • RUGGED AND DURABLE - EASTPUK carriage bolts are made of quality 18-8 (304) Stainless Steel, offering better corrosion resistance and rust protection compared to standard screws. Carriage bolts 1/4 are long-lasting and less prone to damage, and are...
  • VALUE PACKAGING AND EASY TO USE - The bolt kit contains 20pcs carriage bolts (6pcs 1/4 x 5/8, 5pcs 1/4 x 3/4, 4pcs 1/4 x 1-1/4, 3pcs 1/4 x 1-1/2, 2pcs 1/4 x 2) + 20pcs stainless washers + 20pcs hex nuts, designed to stay secure during installation and...
  • DEDICATED SERVICE - At EASTPUK, customer satisfaction is our priority. If you have any questions or concerns, please reach out to us via email, and we’ll address any issues as quickly as possible.
$7.99
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No. 5
EASTPUK (20 Sets) 1/4-20 x 1-1/2 Carriage Bolts with Nuts and Washers, 304 Stainless Steel Round Head Square...
EASTPUK (20 Sets) 1/4-20 x 1-1/2 Carriage Bolts with Nuts and Washers, 304 Stainless Steel Round Head Square...
  • PRODUCT SIZE - Thread Diameter: 1/4", Length: 1-1/2", Thread Pitch: 0.05", Head Diameter: 0.56“, Head Height: 0.15”. Ideal for wood projects, timber frame shed, trailer deck boards, deck construction, outdoor bench rebuild.
  • SECURE AND RELIABLE - The round head and square neck design of carriage bolts ensure a secure fit in square holes. When used with 1/4 hex nuts and flat washers, they provide reliable and stable fastening. Carriage bolts have a dome head and locking neck...
  • RUGGED AND DURABLE - EASTPUK carriage bolts are made of quality 18-8 (304) Stainless Steel, offering better corrosion resistance and rust protection compared to standard screws. Carriage bolts 1/4 are long-lasting and less prone to damage, and are...
  • VALUE PACKAGING AND EASY TO USE - The bolt kit contains 20pcs 1/4 carriage bolts + 20pcs stainless washers + 20pcs hex nuts, designed to stay secure during installation and sink quickly and easily. They are ideal for use at home, in the office, or at...
  • DEDICATED SERVICE - At EASTPUK, customer satisfaction is our priority. If you have any questions or concerns, please reach out to us via email, and we’ll address any issues as quickly as possible.
$8.99
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No. 6
VGBUY 1/4-20 x 1-1/4' Carriage Bolts Screws 24 Sets, 304 Stainless Steel 18-8, Round Head Square Neck...
VGBUY 1/4-20 x 1-1/4" Carriage Bolts Screws 24 Sets, 304 Stainless Steel 18-8, Round Head Square Neck...
  • Strong Carriage Bolts: Carriage bolt is dome head bolt fastener with a locking neck style, which prevents turning when the nut it tightened or removed. Can be used in wood, metal applications
  • Stainless Carriage Bolts: Our 304 stainless steel carriage bolts 1/4 are of excellent corrosion resistance and durability. These carriage bolts 1/4 x 1-1/4 are ideal for both indoor and outdoor use
  • Well Made Carriage Bolts 1-1/4 Inch: All of the stainless steel bolts and hex nuts and flat washers are well manufactured with no burs, smooth-symmetrical head, precise and clean threads
  • Complete Bolts Nuts Washers Kit: You will get 24pcs 1/4-20 x 1-1/4" carriage bolts, 24pcs 1/4-20 hex nuts, 24pcs 1/4" ID flat washers in one package. Standard size, the bolt conforms to ASME B 18.5
  • Versatile: Carriage bolts aren't just for carriages, these bolts can be used on wood projects, timber frame shed build, trailer deck boards, deck project, outdoor bench seat rebuild, etc.
$9.99
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No. 7
1/4' x 2-1/2' (100 Pack) Galvanized Carriage Bolt Kit Grade 307A Includes 1/4' USS Flat Washers (100 pcs) and...
1/4" x 2-1/2" (100 Pack) Galvanized Carriage Bolt Kit Grade 307A Includes 1/4" USS Flat Washers (100 pcs) and...
  • Diameter: 1/4" | Length: 2-1/2" | Head diameter: 0.578" | Nut diameter: 1/4" | Nut wrench size: 7/16" | Washer outside diameter: 47/64"
  • Kit includes 100 Grade 307A carriage bolts, 100 USS thick washers, 100 Grade 2/A hex nuts
  • Hot dip galvanized coating for superior corrosion resistance, Suitable for use in ACQ treaded lumber
  • The flat head provides a semi-flush finish and is perfect for decks, gazebos, pergolas, and other heavy duty applications
  • Meets or Exceeds: ASME B18.5, ASTM A307, ASME B18.2.2, ASTM A563, ASME B18.21.1, ASTM F2329
$39.19
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No. 8
Yinpecly 24 Sets 1/4-20 x 1-1/4' Carriage Bolts Screws, 304 Stainless Steel Round Head Square Neck Carriage...
Yinpecly 24 Sets 1/4-20 x 1-1/4" Carriage Bolts Screws, 304 Stainless Steel Round Head Square Neck Carriage...
  • Package Includes: 24 Pcs Carriage Bolts (1/4-20 x 1-1/4"), 24 Pcs Hex Nuts (1/4"-20), 24 Pcs 1/4" ID Flat Washers and 24 PCS Spring Lock Washers
  • Thread Size: 1/4-20; Thread Pitch: 20 TPI; Thread Type: Coarse Thread
  • Material: Carriage Bolts are made of 304 stainless steel, the carriage bolts and nuts kit is strong and reliable, resistant to corrode, making them suitable for both indoor and outdoor applications
  • Well Made Carriage Bolts: All of the stainless steel bolts and hex nuts and flat washers are well manufactured with no burs, smooth-symmetrical head, precise and clean threads
  • Application: Carriage bolts aren't just for carriages, these bolts can be used on wood projects, timber frame shed build, trailer deck boards, deck project, outdoor bench seat rebuild, etc.
$8.99
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No. 9
1/4-20 x 4 Inch Carriage Bolt Kit, 304 Stainless Steel (18-8) with Hex Nuts & Flat Washers - 10 Sets, Round...
1/4-20 x 4 Inch Carriage Bolt Kit, 304 Stainless Steel (18-8) with Hex Nuts & Flat Washers - 10 Sets, Round...
  • Ready to Use – Save Time & Effort: This complete 10-piece set includes 10 precisely matched 1/4-20 x 4" Carriage Bolts, 10 Hex Nuts, and 10 Flat Washers; No more separate purchases or surprise missing parts—get everything you need to start and finish...
  • Engineered from Grade A2-70 304 (18-8) Stainless Steel, these fasteners deliver significantly greater corrosion resistance and strength compared to zinc-plated or lower-grade alternatives. Designed to perform reliably in both indoor and demanding outdoor...
  • Precision Machining – For a Smooth, Flawless Fit: Every bolt is manufactured to meet ANSI B18.5 standards, ensuring consistent quality, precise threads, and accurate dimensions. This ensures smooth installation, prevents cross-threading, and delivers a...
  • Full Thread Design & Locking Square Neck – Unmatched Strength & Easy Installation: Featuring Full Thread Coverage from neck to tip for maximum nut engagement and superior strength. Moreover, the integrated square neck is designed to bite securely into...
  • Versatile, Heavy-Duty Fastening Solution: Perfect for a wide range of critical applications. From securing deck boards to joists and reinforcing trailer beds and ramps, to building fences, pergolas, and outdoor furniture. Also ideal for agricultural...
$9.79
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Last update on 2026-07-16 / Affiliate links / Images from Amazon Product Advertising API

How to Choose the Best Carriage Bolts

Understanding Carriage Bolt Components

Carriage bolts consist of a smooth, domed head, a square section just below the head, and a threaded shank. The domed head offers a clean finish and prevents injury from sharp edges. The square neck is designed to dig into the material being fastened, preventing rotation during installation and use. The threaded shank allows for secure tightening with a nut.

Key Material Considerations

Carriage bolts are commonly made from several materials, each offering different benefits:
  • Steel: Offers good strength and durability for general-purpose applications. It's often zinc-plated to resist corrosion.
  • Stainless Steel: Provides excellent corrosion resistance, making it ideal for outdoor use or in environments prone to moisture. It's also very strong.
  • Brass: Offers good corrosion resistance and a decorative appearance, but is generally not as strong as steel.
  • Galvanized Steel: Steel treated with a zinc coating for enhanced rust protection, suitable for exterior projects.

Determining the Right Size

Selecting the correct size involves considering two primary dimensions: diameter and length.
  • Diameter: This refers to the width of the threaded shank and dictates the bolt's strength and the size of the hole required. Common diameters include 1/4", 5/16", 3/8", and 1/2".
  • Length: Measure from the underside of the bolt's head to the end of the threaded shank. The bolt should be long enough to pass through all materials and allow for the nut and washer, with a few threads still visible.

Choosing the Right Head Style and Finish

While the domed head is standard, some variations exist. The finish also plays a role in performance and aesthetics. Common finishes include plain (uncoated), zinc-plated (for moderate corrosion resistance), and galvanized (for superior outdoor protection). Ensure the finish matches the environment where the bolt will be used.