Heavy hex nuts are used when more “beef” is needed than in standard hex nuts. Often heavy hex nuts are used in high temperature and high pressure applications, particularly those involving flanged joints. Generally the width across the flats is 1/8 of an inch larger than common hex nuts. The thickness of heavy hex nuts is equal to approximately the nominal diameter, which is about 10% thicker than a regular hex nut.
Get a definition and description of the heavy hex nuts along with applications & industries that commonly employ these fasteners.
What is a Heavy Hex Nut
A heavy hex nut is a hexagonal nut that is thicker and larger across the flats than a standard finished hex nut. It also has a washer face which allows it to hold a more evenly distributed load.
Check out the parts of a heavy hex nut below:
Finished Hex Nuts Vs. Heavy Hex Nuts
Heavy hex nuts are stronger & larger than a finished hex nuts. Check out all of the similarities & differences in our blog post ~ Finished Hex Nuts Vs. Heavy Hex Nuts.
Heavy Hex Nuts Applications
Check out a list of applications that utilize heavy hex nuts.
Offshore Oil & Gas Platforms
Description: Securing structural joints, flanges, and pressure vessels exposed to saltwater, high pressures, and extreme weather.
Heavy hex nuts are critical components in demanding applications, offering superior strength, load distribution, and durability—especially when made from exotic alloys like Inconel, Hastelloy, and Titanium. These specialized fasteners perform reliably in extreme environments such as offshore rigs, aerospace systems, nuclear plants, and chemical processing facilities. Their enhanced performance ensures safety, longevity, and structural integrity where standard nuts would fail. If you’re engineering for high-stakes environments, don’t compromise on fasteners.
Contact us today to request a customized quote—let’s equip your project with precision-engineered, exotic alloy heavy hex nuts built to perform.
Nickel Systems provides high quality exotic grade materials that hold up in the toughest, most severe heat and corrosive environments. With our large inventory of specialty fasteners in stock, we are always ready to answer the call to serve the most challenging applications.
Nickel Systems is not limited to materials covered by ASTM A194. We maintain heavy hex nut inventory in Hastelloy® C (Alloy C276), Carpenter® 20 (Alloy 20) and Duplex 2205. Metric sizes and other alloys can be provided.
