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carriage-bolts

Square Shoulder Round Head Bolts, Carriage Bolts, Step Bolts, Plow Bolts

  • Diameters from 1/4″ through 1″
  • Mild, Steel, Alloy Steel, Stainless Steel, and Bronze
  • Partial or fully threaded, standard or short square shoulder
  1. Custom Shoulder Bolts Per Print or Customer Supplied Specifications
  2. Passivation, Plating, Organic Finishes, and Special Operations
  3. Inch, Metric, Military and Specialized Standards
  4. Reverse Engineering From Sample or Drawings / Print

Cold-formed square neck Carriage Bolts can be customized to meet our customer’s special requirements.

Made in USA | Best Available Lead Times
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  • Description
  • Features
  • Specifications

High-Strength Carriage Bolts and Plow Bolts for Industrial Use

When your structural assembly, heavy equipment, or outdoor project depends on durable fastening, selecting the right carriage bolts or plow bolts can make the difference between long-lasting strength and frequent failures. Whether you're securing thick wooden beams, plow blades, or industrial metal surfaces, large carriage bolts and compatible step bolts must perform under stress, weather, and demanding loads.

When to Use Step Bolts in Your Projects

Step bolts are akin to carriage bolts with a wider and lower but still rounded head used when you need a bearing surface that covers a larger area (e.g. steps, platforms) to avoid wood pull-through. They are ideal when the appearance and load distribution matter. To ensure your project or equipment performs safely and reliably, choose carriage bolts and plow bolts from suppliers you can trust. Browse our range of large carriage bolts, step bolts, and full finish options. Request a quote or shop now to secure high-strength fastening solutions built to last.

Features & Benefits of Carriage and Plow Bolts

  • Strong, secure fastening: Square necks under the head prevent turning; dome-head (carriage) or flat/countersunk heads (plow) allow for clean, flush mounting in critical applications.
  • Material versatility: Available in stainless steel (18-8, 316), grade-5 and grade-8 alloy steels, galvanized or zinc-plated finishes to resist corrosion and wear.
  • Suitable for large sizes: Large carriage bolts support higher shear and tensile loads ideal for heavy equipment, structural timber, and industrial assemblies.
  • Low profile or flush surface options: Plow bolts and certain step bolts provide heads that do not protrude, reducing wear, snagging or aerodynamic drag in some uses.
  • Broad applicability: Use in farming, construction, snow removal, timber framing, deck building, metal-to-wood connections and more.

Solving Common Problems: How the Right Bolt Helps

Problem Solution with Quality Carriage/Plow Bolt
Bolt head protruding causes interference or damage Use plow bolts or countersunk flat-head styles—flush mount, avoids catching or abrasion
Bolt loosening under vibration or shear loads Choose heavy-duty large carriage bolts with appropriate thread engagement and square or ribbed neck; use lock washers or locking nuts as needed
Corrosion in outdoor or wet environments Select stainless steel (316 for marine/salt) or hot-dipped galvanized finishes; pair with matching nuts/washers to avoid dissimilar metal corrosion
Supplier gives inconsistent quality or sizes Select carriage bolt suppliers with clear specs (material grade, thread standards, head type), certifications (ASTM, ISO), and good inventory for large carriage bolts to avoid delays