Value Collection 309778MSC Heavy Hex Nut 3-4 Unc

Product Description

The VALUE COLLECTION 309778MSC is a heavy hex nut threaded to the 3-4 UNC standard with a right-hand thread direction and a 2B class of fit. Made from steel and left uncoated, this nut is built for high-load structural and industrial fastening applications where a standard hex nut lacks the bearing surface or wall thickness required. At 4-5/8 inches across the flats and 2-61/64 inches in height, this is a large-format fastener suited for heavy equipment assembly, structural steel connections, and infrastructure work. Licensed trades and industrial maintenance professionals are the typical end users for a nut of this size class.

This heavy hex nut is used in applications that demand a larger wrench-bearing surface and greater material strength than a standard hex profile provides. Typical install scenarios include structural steel bolting, heavy machinery assembly, and large-diameter pipe flange connections. The UNC thread form is the most common inch-series coarse thread standard in North American industrial use, making this nut widely compatible with UNC-threaded bolts and studs of the corresponding diameter. The uncoated finish is appropriate for environments where a field-applied coating or galvanizing will be added after installation.

Key Features

• 3-4 UNC right-hand thread for broad compatibility with inch-series coarse-thread fasteners
• 2B thread fit class — standard commercial tolerance for reliable engagement with mating 2A bolts and studs
• Heavy hex profile at 4-5/8 inches across the flats provides increased bearing surface versus standard hex
• Steel construction suited for high-load structural and industrial fastening
• Uncoated finish allows field coating or galvanizing after installation
• Does not meet military specifications — intended for commercial and industrial use

Compatibility

Designed as an OEM-style replacement or direct-use heavy hex nut for structural and industrial bolting applications using 3-4 UNC right-hand threaded bolts and studs with a 2A thread class.

Installation Notes

Installation of large-diameter heavy hex nuts at this size class typically requires a calibrated torque wrench or hydraulic torque tool and should be performed by a qualified mechanic, ironworker, or industrial maintenance technician. Always inspect mating bolt or stud threads for damage or contamination before engagement. Follow applicable structural or equipment torque specifications from the project engineer or equipment manufacturer. Ensure the fastener seating surface is clean and flat before applying final torque.