Reviewing popular carriage bolt brands in 2025

The industrial fasteners market shows robust growth, underscoring the importance of selecting the right hardware.

This buying guide reviews top carriage bolt brands. Fastenal earns the best overall spot. It provides an unmatched balance of strength and quality bolt casting. Other contenders for specific needs include:

• Heavy-Duty Use: Hillman Group
• Budget Option: Midwest Fastener
• Corrosion Resistance: Simpson Strong-Tie
• Specialty Finishes: National Bolt & Nut Corp.

For unique projects, a custom fasteners manufacturer can supply a specific carriage bolt. These custom fasteners ensure precise fit and function. The right carriage bolts are critical for project success.

Our 2025 Review Criteria for Top Carriage Bolt Brands

To identify the leading carriage bolt brands, our team established a rigorous testing framework. This process evaluates each brand against critical performance benchmarks, from material composition to long-term durability. We analyzed products to provide a clear comparison of their strength, resilience, and overall value.

Material Quality and Finish

The foundation of a reliable fastener is its material. We scrutinized the base metals and protective coatings that determine a bolt’s lifespan and application suitability.

Steel Grade Analysis (Grade 2, 5, 8)

The grade of steel directly correlates to a bolt’s strength. We verified the minimum tensile strength for the most common grades of high tensile carriage bolts.

Grade 8 high tensile carriage bolts offer the highest strength, making them suitable for critical structural connections. Grade 2 bolts are appropriate for light-duty, non-structural applications.

Stainless Steel Types (18-8, 316)

For projects requiring inherent corrosion resistance, stainless steel carriage bolts are the premier choice. Our analysis focused on the two most prevalent types: 18-8 and 316 stainless. While 18-8 stainless provides excellent general-purpose durability, 316 stainless steel contains molybdenum. This addition gives it superior resistance to chlorides, making it essential for marine or coastal environments.

Protective Coatings (Zinc, Galvanized)

A coating is the first line of defense against corrosion for carbon steel carriage bolts. Hot-dip galvanized coatings offer far greater protection than standard zinc plating. The galvanized process creates a thick, metallurgically bonded layer that resists chipping. According to the American Galvanizers Association, a properly galvanized fastener can last over 50 years even in temperate marine settings.

Strength and Durability Testing

We conducted mechanical tests to quantify the performance of high tensile carriage bolts under stress. These tests followed established industry standards to ensure accurate and repeatable results.

Tensile Strength Evaluation

Tensile strength measures the maximum pulling force a bolt can withstand before fracturing. Using Universal Testing Machines (UTMs) according to ASTM F606 standards, we pulled each bolt to its breaking point. This test is crucial for evaluating high tensile carriage bolts intended for load-bearing applications.

Shear Strength Performance

Shear strength is a bolt’s capacity to resist forces applied perpendicular to its axis. This is critical for joints where components may slide past one another.

As an empirical guide, shear strengths of carbon steel fasteners may be assumed to be approximately 60 percent of their specified minimum tensile strengths. For example, an SAE grade 5 hex cap screw has a specified minimum tensile strength of 120,000 psi. Therefore, for design purposes, its shear strength could be reasonably assumed to be 70,000 psi.

Head and Neck Durability

The distinctive round head and square neck of carriage bolts are key to their function. We tested the durability of these features by measuring their ability to resist stripping and spin-out during installation. A robust head and neck ensure a secure, lasting connection.

Corrosion Resistance Assessment

A bolt’s ability to resist environmental degradation is paramount for long-term durability. We subjected coated and stainless steel bolts to accelerated and real-world weathering tests.

Salt Spray Test Results

We used the ASTM B117 standard to simulate the corrosive effects of a saltwater environment. This neutral salt spray test is a key benchmark for automotive and marine hardware. The test measures how many hours a fastener can endure the salt fog before showing signs of red rust, providing a comparative measure of coating and material durability.

Long-Term Outdoor Exposure

Beyond lab tests, we initiated long-term outdoor exposure trials in various climates. These tests monitor the real-world performance of galvanized, zinc-plated, and stainless steel fasteners. This data provides invaluable insight into the actual service life and long-term durability of different carriage bolts.

Manufacturing Consistency

Consistent manufacturing separates premium carriage bolt brands from lower-quality alternatives. Our team evaluated each brand’s production quality to ensure reliability from one bolt to the next. Inconsistent fasteners can compromise project integrity and cause installation delays.

Dimensional Accuracy

Precise dimensions are non-negotiable for professional results. We used digital calipers to measure the length, diameter, and head dimensions of multiple carriage bolts from each brand. Significant deviations can lead to issues with fit and structural integrity. Correct sizing ensures that a bolt fits the pre-drilled hole perfectly. This precise sizing is critical for achieving the intended clamping force and shear resistance.

Thread Quality and Fit

Clean, well-formed threads are essential for a smooth and secure installation. We assessed thread quality by:

• Visually inspecting for burrs, chips, or flat spots.
• Manually threading a corresponding nut onto each bolt.

Poorly machined threads can cause cross-threading or galling, especially with stainless steel carriage bolts. This can damage the fastener and prevent proper tightening.

Head and Square Neck Uniformity

The square neck beneath the head is a carriage bolt’s most important feature. It is designed to bite into wood or fit into a square hole, preventing the bolt from turning during tightening. We measured the uniformity of the head and neck across samples. A well-defined, consistent square neck provides superior resistance to spin-out, ensuring a reliable connection.

Price and Value Proposition

Cost is always a factor, but the cheapest option is rarely the best value. We analyzed both the upfront cost and the long-term performance to determine the true value of each brand.

Cost-Per-Unit Comparison

To establish a baseline, we compared the cost-per-unit for a standard-sized fastener across all brands. This provides a straightforward look at what you can expect to pay for a common bolt.

This comparison helps identify budget-friendly options for less demanding applications.

Performance-to-Price Ratio

True value comes from balancing cost with performance. A slightly more expensive bolt that offers double the corrosion resistance or significantly higher strength provides a better long-term return on investment.

Our analysis prioritizes the performance-to-price ratio. This metric reveals which brand delivers the most strength, durability, and manufacturing quality for your dollar, ensuring you get the best fastener for your project’s specific needs.

This approach helps you choose a fastener that will perform reliably for the life of your project, preventing costly future repairs.

In-Depth Reviews: The Best Carriage Bolts of 2025

Our comprehensive reviews provide a detailed look at the top-performing carriage bolt brands of the year. Each brand underwent the same rigorous testing protocol. The results highlight the specific strengths and ideal uses for each, helping you select the perfect fastener for your project.

Fastenal: Best Overall Performance

Fastenal earns its top spot by delivering exceptional quality across every metric. These fasteners are the benchmark for reliability and performance in the industry.

Performance Against Criteria

Fastenal’s products demonstrated near-flawless manufacturing consistency. Our team measured minimal dimensional variance and observed perfectly formed threads on every sample. Their Grade 5 and Grade 8 high tensile carriage bolts consistently exceeded the minimum PSI strength requirements in our tensile tests. The hot-dip galvanized coatings provided outstanding corrosion resistance, lasting significantly longer than competitors in the salt spray test. This level of quality ensures predictable performance and long-term durability.

Pros and Cons

Pros:

• Superior manufacturing quality and consistency
• Exceptional strength in high tensile carriage bolts
• Excellent corrosion resistance and finish durability
• Trusted by professionals for critical applications

Cons:

• Higher cost-per-unit compared to budget brands
• Primarily available through industrial supply channels

Ideal Project Applications

Fastenal carriage bolts are the premier choice for projects where failure is not an option. Their reliability makes them ideal for:

• Structural connections in residential and commercial construction
• Heavy-duty machinery assembly
• High-end deck and pergola construction
• Any application demanding maximum strength and durability

Hillman Group: Best for Heavy-Duty Applications

The Hillman Group specializes in fasteners engineered for strength. Their products are a top choice for professionals who require maximum load-bearing capacity and robust performance.

Performance Against Criteria

Hillman’s high tensile carriage bolts were standouts in our strength and durability testing. Their Grade 8 bolts, in particular, offered some of the highest tensile and shear strength values recorded. The head and square neck design provided excellent bite, resisting spin-out even under high torque. The brand’s Power Pro line is specifically designed for demanding wood construction projects.

Power Pro fasteners are ideal for a wide range of professional jobs. They meet the demands of carpenters, masons, and metal workers for projects from the foundation to the roof.

Common applications specified for these heavy-duty fasteners include:

• Decks
• Subfloor
• Framing
• Fences

Pros and Cons

Pros:

• Exceptional tensile and shear strength
• Excellent head and neck durability for secure installation
• Widely available in retail hardware stores
• Trusted brand for structural wood projects

Cons:

• Standard coatings offer average corrosion resistance
• Higher price point than generic hardware

Ideal Project Applications

Choose Hillman Group when your project’s structural integrity is the top priority. These high tensile carriage bolts excel in:

• Timber framing and post-and-beam construction
• Building retaining walls
• Assembling large outdoor playsets
• Any project involving heavy lumber and significant structural loads

Midwest Fastener: Best Budget-Friendly Option

Midwest Fastener provides an accessible and affordable option for a wide range of everyday projects. These carriage bolts offer acceptable performance for light-duty applications where cost is a primary consideration.

Performance Against Criteria

Midwest Fastener’s products met the basic requirements for Grade 2 steel. Our reviews found their dimensional accuracy and thread quality to be adequate for general use, though less consistent than premium brands. The standard zinc plating provides minimal corrosion protection, making these bolts best suited for indoor or dry environments. While they do not compete with the strength of high tensile carriage bolts, they perform reliably in non-structural roles. Many positive customer reviews confirm their value for DIY projects. User reviews often praise the brand’s affordability.

Pros and Cons

Pros:

• Extremely low cost-per-unit
• Widely available in convenient bulk packaging
• Sufficient strength for light-duty DIY tasks

Cons:

• Inconsistent manufacturing tolerances
• Low corrosion resistance
• Not suitable for structural or outdoor applications

Ideal Project Applications

Midwest Fastener is the go-to choice for budget-conscious builders and hobbyists. These carriage bolts are perfect for:

• Indoor furniture assembly
• Building workshop shelving and storage
• Light-duty garden projects like raised beds
• General household repairs and non-load-bearing tasks

Simpson Strong-Tie: Best for Corrosion Resistance

When a project faces harsh weather, moisture, or coastal air, Simpson Strong-Tie provides the ultimate defense. The brand has built its reputation on engineering fasteners that withstand the elements, making them the undisputed leader for corrosion resistance.

Performance Against Criteria

Simpson Strong-Tie excelled in our corrosion assessments. Their products undergo extensive independent testing to validate their durability. This process ensures superior performance in real-world conditions.

• Fasteners endure rigorous salt spray tests, including the ASTM B117 continuous moisture test and the ASTM G85 cyclic wet/dry test.
• Each test runs for approximately 1,440 hours, simulating long-term exposure to corrosive environments.
• Coatings must perform equal to or better than a hot-dip galvanized benchmark to pass.
• Specialized coatings like Double-Barrier and Quik Guard® successfully pass these demanding tests. They are approved for use with preservative-treated lumber and in ground-contact applications.

This commitment to verified resistance gives builders confidence. The manufacturing consistency is also excellent, with uniform dimensions and clean threads that prevent installation issues.

Pros and Cons

Pros:

• Industry-leading corrosion resistance and coating technology
• Verified performance through independent ASTM testing
• Approved for use with modern treated lumber
• Excellent manufacturing quality and reliability

Cons:

• Premium price point reflects advanced coating technology
• May be overkill for indoor or dry applications

Ideal Project Applications

Simpson Strong-Tie carriage bolts are essential for projects where longevity in harsh environments is critical. They are the top choice for:

• Coastal construction, including decks, docks, and boardwalks
• Projects using pressure-treated lumber
• Building fences and retaining walls in wet climates
• Any outdoor structure requiring maximum protection from moisture and salt

National Bolt & Nut Corp: Best for Specialty Finishes

National Bolt & Nut Corp. carves out its niche by offering an impressive array of specialty finishes. This brand is the ideal choice for projects where aesthetics are just as important as function, providing builders and artisans with unique decorative options.

Performance Against Criteria

National Bolt & Nut Corp. focuses on the final look of the fastener. Our review noted their exceptional finish quality, particularly in black oxide and thermal black oxide coatings. These finishes were consistent, durable, and visually appealing. The underlying carriage bolts meet standard Grade 2 or Grade 5 specifications, providing adequate strength for most decorative and light structural applications.

While not designed for extreme load-bearing roles, the brand’s products offer reliable performance for their intended use. The dimensional accuracy and thread quality were consistent, ensuring a good fit and finish for visible connections.

Their strength is not in raw power but in providing a polished, professional look that other brands do not offer.

Pros and Cons

Pros:

• Wide selection of specialty and decorative finishes
• High-quality, consistent coating application
• Good for projects where hardware is a design element
• Reliable performance for non-structural tasks

Cons:

• Not intended for heavy-duty structural loads
• Specialty finishes offer limited corrosion protection compared to galvanizing

Ideal Project Applications

Select National Bolt & Nut Corp. when the appearance of your hardware matters. These decorative carriage bolts are perfect for:

• Assembling rustic or industrial-style furniture
• Installing decorative gates and barn doors
• Custom woodworking and artisan projects
• Any application where the bolt head is a visible design feature

Comparative Analysis: 2025 Carriage Bolt Showdown

Choosing the right fastener requires a direct comparison of material, strength, and finish. This showdown breaks down the key differences between popular carriage bolts to help you match the right product to your project’s demands.

Strength Showdown: High Tensile Carriage Bolts

Grade 5 vs. Grade 8 Steel

The grade of a bolt defines its strength. High tensile carriage bolts are essential for load-bearing connections. Grade 5 bolts are strong and suitable for many applications. Grade 8 high tensile carriage bolts, however, offer a significant step up in strength. These high-strength fasteners are made from a superior alloy steel that is quenched and tempered for maximum hardness. This process gives them a much higher tensile strength, making them the top choice for critical structural applications.

Structural Load Capacity

The superior strength of Grade 8 high tensile carriage bolts directly translates to a higher load capacity. For projects like vehicle frame assembly or heavy machinery mounting, these high tensile carriage bolts provide an essential safety margin. Grade 5 high tensile carriage bolts are sufficient for building decks and playsets. Grade 8 high tensile carriage bolts are necessary where extreme forces are expected. Using the correct grade ensures long-term structural integrity and safety.

Durability Deep Dive: Stainless Steel Carriage Bolts

18-8 vs. 316 Stainless Steel

Stainless steel carriage bolts provide inherent corrosion resistance without needing a protective coating. The two most common types are 18-8 and 316 stainless. 18-8 stainless steel offers excellent protection against general corrosion and is a great choice for most outdoor projects. For superior durability, 316 stainless steel includes molybdenum. This element dramatically increases its resistance to chlorides found in saltwater and de-icing chemicals.

Marine and Coastal Suitability

The added protection from 316 stainless makes it the only reliable choice for marine environments.

Projects near the coast, on boats, or in saltwater splash zones demand the enhanced corrosion resistance of 316 stainless. Using a lesser material in these conditions can lead to premature failure and costly repairs.

This level of durability ensures fasteners remain secure and rust-free for years, even in the harshest settings.

Finish and Coating Effectiveness

Zinc-Plated vs. Hot-Dip Galvanized

For carbon steel high tensile carriage bolts, the coating is the primary defense against rust. Zinc plating offers a thin, bright finish suitable for indoor use. Hot-dip galvanized coatings provide far greater protection. The hot-dip galvanized process creates a thick, metallurgically bonded layer that delivers decades of maintenance-free service. In contrast, zinc-plated steel is best for short-to-medium indoor service. This makes galvanized fasteners the standard for outdoor construction.

Black Oxide and Other Finishes

Other finishes offer specific benefits. Black oxide provides mild corrosion resistance and a desirable black finish for aesthetic applications. It is popular for furniture and indoor fixtures where appearance is key. These specialty finishes, however, do not match the robust durability of a hot-dip galvanized coating for outdoor use.

Head-to-Head Value Breakdown

The best value depends entirely on the user. A weekend DIYer and a professional contractor have different priorities, budgets, and performance requirements. This breakdown analyzes value from both perspectives.

DIY Project Value

Do-it-yourself enthusiasts typically prioritize cost and convenience for smaller, non-structural projects. Value for this group means getting the job done reliably without overspending on unnecessary features. For general household repairs, indoor furniture assembly, and light-duty workshop projects, budget-friendly brands deliver the best return.

Midwest Fastener stands out as the clear value leader for the DIY community. The brand offers an extremely low cost-per-unit, often in convenient bulk packages. This makes it easy to stock a workshop for various future tasks. Midwest Fastener offers the most economical carriage bolts for these tasks.

For projects like building a simple bookshelf or a small storage rack, the strength of a basic Grade 2 bolt is more than sufficient. The primary goal is affordability and immediate availability, which Midwest Fastener provides.

For projects requiring a bit more strength, such as a backyard playset or a garden bench, The Hillman Group presents a valuable step up. It is widely available in retail stores and provides a noticeable increase in strength and quality without the premium cost of industrial-grade fasteners.

Professional Contractor Value

A professional contractor defines value through performance, reliability, and long-term liability. A fastener failure can lead to costly rework, reputational damage, and safety issues. Therefore, the cheapest option is rarely the best value. Professionals select specific carriage bolts based on project specifications to ensure structural integrity and code compliance. The initial investment in a premium fastener is a small price for long-term peace of mind.

The value proposition for a contractor is tied directly to the application.

For a contractor, time is also money. The superior manufacturing consistency of brands like Fastenal and Simpson Strong-Tie prevents installation delays caused by bad threads or inconsistent dimensions. This efficiency contributes directly to the project’s profitability, making premium fasteners a wise business decision.

Specialty Carriage Bolts: Beyond the Basics

Standard hardware does not always meet the unique demands of specialized projects. For restoration work, advanced engineering, or critical infrastructure, specialty fasteners provide solutions beyond off-the-shelf availability. This includes custom manufacturing and sourcing from specialized domestic and international suppliers.

Exploring Custom Solutions from Qewit

Custom manufacturers like Qewit offer tailored solutions when standard parts fall short. They provide fasteners built to exact project specifications, ensuring a perfect fit and optimal performance.

Custom Lengths and Diameters

Some projects require non-standard dimensions for structural integrity. A custom manufacturer can produce high tensile carriage bolts with specific lengths and diameters. This capability is essential for historical restorations or unique engineering designs where pre-drilled holes do not match common sizes.

Unique Material Requests

Material science offers alloys with specific properties for extreme environments. Custom suppliers can fabricate carriage bolts from unique materials beyond typical steel grades. This allows engineers to specify fasteners with enhanced heat resistance, non-magnetic properties, or other specialized characteristics.

International Brands to Watch

The global market provides access to a vast range of fastener manufacturers. Companies in this space often offer extensive product lines and competitive pricing for large-volume orders.

Jiaxing Qimu Fastener Co.

Jiaxing Qimu Trading Co., Ltd. is a versatile international supplier. The company produces a wide array of fasteners for various industries. Their product catalog includes:

• Thread Rods and Studs
• Screws (Drywall, Self-Drilling)
• Nuts and Washers
• Bolts and Anchors

They manufacture products to DIN, ANSI, and ISO standards. Their material options include carbon steel grades up to 12.9, suitable for high tensile carriage bolts.

Shanghai Hengrui Industry

Shanghai Hengrui Industry Co., Ltd. has over 15 years of experience as a custom fastener manufacturer. The company produces an exhaustive list of standard and non-standard parts. Their bolt offerings include hex, flange, plow, and T-head bolts, alongside many other types. They are a key source for high tensile carriage bolts for industrial machinery and construction.

Sourcing from US Bolt Manufacturing Inc.

Domestic manufacturers provide critical advantages for high-stakes projects. They offer superior quality control, material traceability, and adherence to stringent national standards.

Domestic Manufacturing Advantages

U.S. Bolt Manufacturing Inc. holds numerous certifications, including API Q1, ISO 9001:2015, and Pressure Equipment Directive (PED) compliance. This verified quality assurance gives contractors confidence. Sourcing domestically also simplifies logistics and supports the national economy.

Focus on Critical Applications

U.S. Bolt Manufacturing Inc. engineers high tensile carriage bolts for safety-related and critical service applications. Their products are built for the most demanding environments imaginable.

These fasteners serve industries where failure is catastrophic. Key applications include deep-water offshore equipment, power generation turbines, and nuclear facilities. Their fasteners use fully traceable, nuclear-grade materials machined to precise tolerances, ensuring ultimate reliability.

Project-Specific Recommendations

Selecting the right fastener is critical for project success. These expert recommendations match specific project needs with the ideal carriage bolt brand and material for optimal performance and durability.

For Deck and Fence Building

Top Choice for Structural Integrity

For the main structural framework of a deck or fence, strength is the primary concern. High tensile carriage bolts from Hillman Group, particularly their Grade 5 options, provide the necessary load-bearing capacity. These high tensile carriage bolts ensure that posts, beams, and joists form a secure and lasting connection, preventing structural failure over time.

Best Choice for Weather Exposure

Outdoor structures require robust protection against the elements. Hot-dip galvanized fasteners are the industry standard for this purpose. Simpson Strong-Tie offers superior galvanized high tensile carriage bolts that provide excellent durability. The thick galvanized coating creates a tough barrier against moisture and atmospheric chemicals.

It is essential to match the fastener material to the wood type. Modern pressure-treated lumber and certain woods require specific protection:

• Woods rich in tannins, like cedar and redwood, can cause staining and corrosion with unprotected steel.
• Lumber treated with Alkaline Copper Quaternary (ACQ) is highly corrosive to standard steel.
• For these applications, hot-dip galvanized or stainless steel fasteners are mandatory to prevent galvanic corrosion and ensure long-term durability.

For Outdoor Playsets and Furniture

Safest and Most Durable Option

Safety is paramount when building playsets or outdoor furniture. The robust construction of high tensile carriage bolts from Fastenal or Hillman Group offers peace of mind. Their consistent manufacturing and high strength ratings ensure that all connections remain tight and secure, even under the stress of active use. Using these high tensile carriage bolts guarantees structural integrity.

Best Finish for Aesthetics

When hardware is a visible design element, aesthetics become important. National Bolt & Nut Corp. excels by providing carriage bolts with specialty finishes like black oxide. These decorative options are perfect for rustic furniture or custom pieces where the bolt heads contribute to the overall style.

For Marine and Coastal Applications

Ultimate Corrosion-Proof Choice

Saltwater environments demand the highest level of corrosion resistance. For these applications, 316 stainless steel is the only reliable choice. The molybdenum content in 316 stainless steel provides superior protection against chlorides.

Simpson Strong-Tie is a leading provider of 316 stainless fasteners for these critical marine projects.

Runner-Up for Brackish Environments

For environments with less salinity, such as brackish water or freshwater lakes, other materials offer excellent performance. Silicon bronze fasteners are highly resistant to corrosion and marine organism growth. Additionally, 18-8 (or 304) stainless steel provides a cost-effective solution for freshwater applications where the extreme resistance of 316 stainless is not required. These recommendations ensure lasting performance.

For Indoor and Light-Duty DIY

Indoor projects and light-duty DIY tasks have different requirements than heavy construction. Cost, convenience, and appearance often take priority over maximum strength and corrosion resistance. The right fastener for these jobs provides reliable performance without unnecessary expense.

Most Economical Choice

For the budget-conscious DIY enthusiast, Midwest Fastener is the undisputed leader. The brand offers an exceptionally low cost-per-unit, making it ideal for stocking a workshop. These fasteners are typically available in bulk quantities, providing great value for numerous small projects.

The strength of a standard Grade 2 bolt is more than adequate for most indoor, non-load-bearing applications. Projects like building garage shelving, assembling workbenches, or creating simple storage solutions do not require the high tensile strength of premium bolts. Midwest Fastener delivers the necessary performance for these tasks at the lowest possible price point.

Pro Tip for DIYers: For indoor projects where the hardware will not be exposed to moisture, a standard zinc-plated finish is sufficient. This provides basic rust protection and keeps costs to a minimum, making it the smart choice for general household repairs.

Choosing an economical option like Midwest Fastener allows hobbyists and homeowners to complete their projects effectively while staying within budget. The brand provides a practical and affordable solution for a wide range of everyday tasks.

Best for Furniture Assembly

Furniture assembly often involves balancing function with aesthetics. The choice of hardware can significantly impact the final look of a piece. For visible connections where the bolt head is part of the design, National Bolt & Nut Corp. is the best choice. Their specialty finishes, such as black oxide or thermal black, offer a decorative touch that enhances rustic, industrial, or custom-built furniture. These carriage bolts provide a clean, professional appearance that standard hardware cannot match.

For connections that are hidden from view, a more standard and economical option is perfectly suitable. The zinc-plated bolts from Midwest Fastener or The Hillman Group provide the necessary clamping force for a sturdy build.

This table breaks down the best options for furniture projects:

Selecting the right fastener ensures that the furniture is not only structurally sound but also meets the desired aesthetic.

Fastenal leads the top carriage bolt brands in 2025. It offers superior materials, flawless manufacturing, and exceptional durability. For maximum strength, Hillman Group’s high-grade options are ideal. Midwest Fastener is the clear winner for value on light-duty projects. When facing harsh weather, the superior corrosion resistance of Simpson Strong-Tie’s galvanized or stainless options is essential. The durability of galvanized and stainless steel is unmatched. Make your purchase with confidence by matching your project’s demands—strength, environment, or budget—to the brand that excels in that category. This ensures you select the best carriage bolts for the job.

FAQ

What is a carriage bolt?

A carriage bolt is a type of fastener with a smooth, domed head and a square neck. The square neck fits into a square hole or bites into wood. This design prevents the bolt from turning when a user tightens the nut.

How do I choose the right bolt grade?

A user selects a bolt grade based on the project’s strength requirements. Higher grades provide greater tensile strength for load-bearing applications. This table offers a general guide.

When should I use stainless steel vs. galvanized bolts?

The project’s environment determines the best choice for corrosion resistance. Each material offers specific protection against moisture and chemicals.

Use hot-dip galvanized bolts for general outdoor construction. Choose 316 stainless steel for marine, coastal, or high-corrosion environments to prevent premature failure and ensure maximum longevity.

Can I reuse old carriage bolts?

Professionals advise against reusing high tensile carriage bolts in structural applications. Tightening can stretch the bolt, compromising its strength. For safety and reliability, always use new fasteners for critical connections. Old bolts are only suitable for non-load-bearing mock-ups.

What is the purpose of the square neck?

The square neck is the carriage bolt’s key feature. It locks into the wood or metal of the material being fastened. This self-locking action allows a builder to tighten the nut from one side without needing to hold the bolt head.

Do I need a washer with a carriage bolt?

Yes, a user should almost always place a washer under the nut. A washer serves two main purposes:

• It distributes the clamping force over a wider area.
• It prevents the nut from damaging the material’s surface during tightening.

How tight should I make a carriage bolt?

A user should tighten a carriage bolt to the project’s specified torque value. Over-tightening can damage the wood or stretch the bolt, reducing its strength. Under-tightening creates a loose connection. Always consult engineering specifications for critical structural joints.