Zinc Plated Steel Carriage Bolt, Oval Head, 5/16"-18, 5" Length (Pack of 50)

Carriage Bolts or Carriage Screws have a square neck that keeps them from turning once tightened. Use in square holes for wood-to-wood and wood-to-metal fastening. Length is measured from under the head.Steels are designated by a 4 number SAE Steel grade. The first two digits indicate the primary materials used to form the steel. The last 2 digits identify the percentage of carbon for the alloy (in hundredths). The steel used in these fasteners has a tensile strength ranging from 100,000 to 150,000 psi (pounds per square inch). Similar to a flat-head style, the oval head style has a slightly convex top surface; it is typically used for appearance. A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine. Coarse threads are better when working with brittle materials; they are sturdier and are easier to thread and unthread compared to fine. Coarse threading also allows for thicker coatings and platings.

• Carriage Bolts have a domed head with a square neck to prevent spinning
• Zinc Plated Steel fasteners are suitable where strength and corrosion resistance are primary considerations
• Oval head style for recessed finish with a slightly rounded surface
• Length is measured from under the head
• Coarse threads are better for brittle materials, and will assemble and disassemble more quickly than fine threads