Midland Industries 18040L Light Pattern Hex Nut 5/8 in

Product Description

The MIDLAND INDUSTRIES 18040L is a light pattern hex nut designed for 5/8-inch compression fittings in plumbing and fluid-handling applications. Machined from brass, this nut provides a secure, leak-resistant connection when used with compression-style tubing assemblies. It measures 0.62 inches in length with a 0.94-inch hex profile and carries a 13/16-18 thread size. Rated to 150 psi and suitable for temperatures ranging from -65 to 250 degrees F, it handles the demands of both residential and light commercial service work. Plumbers, HVAC technicians, and gas fitters reach for this type of fitting nut when completing or repairing compression-style tube connections.

This compression hex nut is suited for use with brass, copper, aluminum, and thermoplastic tubing. It fits into typical service scenarios such as water supply lines, refrigeration tubing connections, instrument lines, and pneumatic assemblies where compression-style fittings are specified. The light pattern design reduces material weight while maintaining the structural integrity needed for standard-pressure service. It is appropriate for both new installation and field repair work across residential and commercial plumbing and mechanical systems.

Key Features

• Brass construction for corrosion resistance and reliable sealing in compression assemblies
• Rated to 150 psi for standard-pressure plumbing and mechanical service
• Temperature range of -65 to 250 degrees F covers refrigeration through hot-water applications
• 13/16-18 thread size for precise fit on compatible compression fittings
• Light pattern hex profile reduces weight while maintaining adequate wrench engagement
• Compatible with brass, copper, aluminum, and thermoplastic tubing types

Compatibility

Designed for use with brass, copper, aluminum, and thermoplastic tubing in 5/8-inch compression fitting assemblies. Suitable as an OEM-style replacement or new-installation component wherever a 5/8-inch compression hex nut with 13/16-18 thread is required.

Installation Notes

Installation is typically performed by a licensed plumber or mechanical contractor. Shut off the water or fluid supply and depressurize the line before removing or installing any compression fitting components. Use an appropriately sized open-end or adjustable wrench on the hex flats - do not overtighten, as brass compression nuts are subject to thread damage if forced. Ensure the tubing end is cut cleanly and squarely and that the ferrule is correctly seated before torquing the nut.