Value Collection 212617 Left Hand Hex Jam Nut 1/2-20 Unf

Product Description

The VALUE COLLECTION 212617 is a left-hand thread hex jam nut designed for fastening applications where standard right-hand threads are not suitable. Machined from steel with a zinc clear finish, this nut measures 0.75 inches across the flats and 0.3125 inches in height. The 1/2-20 UNF thread specification indicates a half-inch nominal diameter with 20 threads per inch on a Unified National Fine thread form. Jam nuts are used to lock a standard nut in place or to serve as a low-profile fastener where limited axial space is available. This part is sold in a package quantity of 50.

Left-hand hex jam nuts are used in mechanical assemblies where vibration or rotational direction would cause a right-hand nut to loosen. Common applications include rotating shafts, tensioning rods, and specialized mechanical linkages found in industrial, HVAC, and plumbing equipment. The zinc clear finish provides a basic level of corrosion resistance for general indoor or sheltered installations. Plumbers, pipefitters, HVAC technicians, and mechanical contractors working on equipment assemblies may encounter this fastener as a component-level hardware item.

Key Features

• Left-hand UNF thread prevents loosening in counter-clockwise rotating or vibrating assemblies
• 1/2-20 UNF thread form for precise, fine-pitch fastening
• 0.75 inches across flats for use with standard hex tooling
• Low-profile jam nut height of 0.3125 inches suits tight axial clearances
• Zinc clear finish offers basic corrosion protection
• Packaged in quantities of 50 for service stock or job-site use

Compatibility

Designed for use with 1/2-20 UNF left-hand threaded fastener assemblies. Verify thread direction and pitch before installation, as left-hand nuts are not interchangeable with standard right-hand hardware.

Installation Notes

Installation requires a standard hex wrench or open-end wrench sized for 0.75-inch across-flats hex fasteners. Left-hand threads tighten counter-clockwise, which is the reverse of standard practice - confirm thread direction before applying torque to avoid cross-threading or component damage. De-energize or depressurize any system before servicing mechanical fastener assemblies. Follow applicable mechanical and equipment codes for the system being serviced.