ASTM A490 is a standard specification for high-strength, heat-treated alloy steel bolts for structural steel joints. These bolts are designed for use in structural connections in buildings, bridges, and other structures. The bolts are made from a medium carbon alloy steel and are heat-treated to achieve a minimum tensile strength of 150 ksi. The standard also includes requirements for chemical composition, mechanical properties, and testing procedures. The A490 bolts are similar to A325 bolts but are made to a higher strength level and are intended for use in high-strength structural connections and in environments where corrosion resistance is important.
The standard dimensions for A490 bolts include:
- Nominal size (diameter): from 1/2 inch to 1-1/2 inches
- Threads: Unified National Coarse (UNC) or Unified National Fine (UNF)
- Thread Length: The minimum thread length is equal to the nominal diameter plus 1 inch.
- Head: Heavy Hex Head
- Length: The length of the bolt is measured from the underhead bearing surface to the extreme end of the bolt.
Additional dimensions such as thread length, head and body diameter, fillet radius, and minimum and maximum body length are also included in the ASTM A490 specification. It is important to note that the manufacturer must provide the dimensional information, and it should be verified by the user.