MIDWEST FASTENER CORP 64496 1"-8 Zinc Plated Steel Coarse Thread Square Nuts 3PK

Square nuts for high-vibration joints

These zinc-plated steel square nuts feature a 1"-8 coarse thread and come in a pack of three. The four-sided design increases contact area with the fastened part, providing greater resistance to loosening under vibration. They are intended for use with matching square-headed bolts in structural or mechanical assemblies. Builders who need a hex-drive fastener will find these incompatible with standard tools.

Behaviour under sustained load

The coarse thread and enlarged bearing surface maintain clamp force when subjected to repeated vibration or thermal cycling. Greater friction between the flat faces resists rotational loosening more effectively than a hex nut of the same nominal size. However, the same geometry also increases the torque required to achieve a given preload, so installation takes more effort. Applications requiring frequent disassembly may find the higher tightening resistance inconvenient.

Corrosion protection and installation

Zinc plating provides a sacrificial barrier against rust in typical indoor or sheltered outdoor environments. The steel substrate handles normal structural loads without yielding. No lubricant is included, so applying an anti-seize compound during assembly is advisable to prevent galling. Buyers who need stainless steel for marine exposure or food-grade service should select a different material.