Shopping Cart

Your cart is empty.

Your cart is empty.

Prime-Line 9063153 Carriage Bolts, 5/16 in.-18 X 4 in., A307 Grade A Zinc Plated Steel, 50-Pack

4.9 (4) Write Review
Free shipping on orders over $29.99

$23.53

$ 11 .51 $11.51

In Stock

About this item

  • Size: 5/16 inch-18 X 4 inch
  • Features a smooth rounded head as opposed to a standard hex head
  • Square shoulder allows for nut to be tightened or loosened
  • Often used in cases where a protruding bolt head could cause injury
  • Nuts and washers not included, ensure washers and nuts are same diameter


Carriage bolts feature a slightly rounded head and have no exposed sharp edges when fully fastened. Due to that reason, they are often used when a more aesthetic look is desired. They are commonly used on docks and on playground equipment or in cases where it may be difficult to reach the bolt head with a tool. The square shoulder on carriage bolts help to hold it in place while the nut is fastened.


Chelsea Tamte-Horan
Reviewed in the United States on April 30, 2024
Shipping timeline completely off. Don’t offer next day shipping if you’re not capable of fulfillment.
William Lamb
Reviewed in Canada on July 13, 2023
The only 5/16x18x4” bolt I purchase
steve rackliff
Reviewed in the United States on November 9, 2019
good price
Shaun
Reviewed in the United States on April 7, 2018
Exactly what I was looking for.