10N40 - ESAB Fuel Gas Hose Nut, B-Size 5/8-18 LH

Technical Overview of the ESAB 10N40 Hose Nut

The ESAB 10N40 is a precision-engineered brass hose nut designed specifically for industrial oxy-fuel welding and cutting applications. This component is critical for maintaining the integrity and safety of gas distribution systems. It features a standard B-Size 5/8"-18 thread with a Left-Hand (LH) orientation. In the welding industry, the distinction between thread directions is a primary safety control; left-hand threads are exclusively reserved for fuel gases (such as Acetylene, Propane, Propylene, and Natural Gas) to physically prevent the accidental connection of a fuel line to an oxygen or inert gas outlet, which use right-hand threads.

Manufactured from high-grade brass, this nut offers excellent machinability and resistance to corrosion and wear, ensuring a long service life even in harsh workshop environments. The nut is designed to mate with standard hose nipples (barbs) and secure them to regulators, torch handles, or machine inlets. The external hex geometry allows for easy tightening with a standard wrench, while the identifying groove or notch cut into the hex vertices is the universal visual indicator for left-hand threads, allowing technicians to verify safety compliance at a glance.

This fitting is an essential component for MRO (Maintenance, Repair, and Operations) inventories, allowing for the immediate repair of damaged hose terminations or the fabrication of custom hose assemblies. It adheres to Compressed Gas Association (CGA) standards for B-size connections, ensuring compatibility across a wide range of equipment brands and models.

Key Technical Specifications

• Thread Specification: 5/8"-18 UNF
• Thread Direction: Left Hand (Counter-clockwise to tighten)
• Material: Solid Brass
• Standard: CGA "B" Size
• Marking: Notched hex for LH identification