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Originally Posted On: Know Your Nuts: Structural Nuts (mudgefasteners.com)

For our third edition of Know Your Nuts, we’re going to review the two most common types of structural nuts. The category of “structural nuts” includes heavy hex nuts that meet ASTM A194 GR. 2H, ASTM A563 GR. C, and ASTM A563 GR. DH specifications.

Grade 2H Nuts

Grade 2H nuts are a type of heavy hex nuts that distribute loads over a larger area, due to their size being about ten percent taller and ten percent wider and taller than standard hex nuts. Because Grade 2H nuts are similar in strength to Grade 9 bolts – roughly 20% stronger than typical steel nuts – uses in heavy machinery are quite common, such as assemblies in earth-moving equipment.

Grade DH Nuts

Grade DH nuts are heavy hex nuts made from medium carbon steel that have been heat treated. Designed and recommended to secure F3125 A490 structural bolts in assemblies, these nuts are often marked by the letters “DH”, although they are not required to be marked unless specified by the purchaser.

If you have further questions about structural nuts, please don’t hesitate to contact us for more information.