What Are Heavy Hex Bolts?

Commonly used in a wide variety of applications, heavy hex bolts have a larger and thicker head than regular or standard hex bolts. This fastener is available in different sizes, both lengths and diameters, although all come with a hex head. Some types are threaded all the way up the shaft, while others have a smooth shoulder area. All are designed to be used with hex nuts for a secure fit in construction projects, for repairs and in automotive applications.

Required By Specifications

                                                 

Hex bolts are made with different metals such as regular grades and stainless steel. The common 18-8 grade is used often. These type of bolts also come with various platings such as zinc, cadmium or hot dipped galvanized.

Heavy hex bolts are required based on a number of different ASTM bolt specifications. In the chemical and petroleum industries the A193 specification calls for heavy hex bolts and nuts in high heat conditions. The A320 standard covers extremely low temperature conditions and requires the use of heavy hex bolts. Also in ASTM specifications the A307 standard dictates that heavy hex bolts are required in situations where the flanged joints within piping systems are made with cast iron flanges.

As well as the standards above, the A490 and A325 specifications call for heavy hex bolts, but with a shorter thread than the others.

Common Industrial Uses

Besides the industries mentioned above, heavy hex bolts are often seen in the following industrial sectors:

* Steel Fabrication
* Construction of railroad systems
* Pumps and Water treatment
* Construction of Modular Buildings
* Renewable and Alternative Energy

Corrosion Resistance Treatment Issues

When a heavy hex bolt is hot-dip galvanized the treatment results in somewhere between 2.2 and 5 mils of thickness being added. This can cause an issue in the threaded portion of the bolt, so galvanized varieties are tapped to help increase the corrosion resistance.

This common industrial fastener is used with success in many different circumstances. Heavy hex bolts are strong and well designed to meet the specifications and needs of your project.