Marson M39359 Insert Tool Mandrel 5/16-18

Product Description

The MARSON M39359 is a 5/16-18 threaded mandrel designed for use with rivet nut and threaded insert installation tools. Mandrels are the threaded nose piece that engages the insert during the setting cycle, pulling the body of the rivet nut or threaded insert to form a clinch on the back side of the workpiece. This mandrel is a replacement or spare component sized to the 5/16-18 UNC thread standard and is compatible with the MARSON 39300 tool platform. Technicians in automotive, HVAC, fabrication, and general assembly trades rely on properly matched mandrels to ensure consistent insert setting and to avoid stripped or misset fasteners.

This mandrel fits applications where 5/16-18 threaded inserts are being installed into sheet metal, thin-wall tubing, or panel assemblies. It is a direct-fit component for the MARSON 39300 tool series and is sold as a single unit. Rivet nut installation is common in situations where only one side of the workpiece is accessible and a permanent threaded anchor is required. Fabricators, automotive technicians, and HVAC sheet metal installers are the primary users.

Key Features

• Sized for 5/16-18 UNC threaded inserts
• Designed for use with MARSON 39300 insert installation tools
• Replacement mandrel allows quick thread-size changeover on compatible tools
• Lightweight at 0.3 pounds for easy handling during install

Compatibility

Designed for use with the MARSON 39300 rivet nut and threaded insert tool. Intended for setting 5/16-18 threaded inserts.

Installation Notes

Thread the mandrel securely into the nose assembly of the compatible tool before beginning insert installation. Ensure the mandrel thread engagement is complete before applying setting force to avoid cross-threading or mandrel damage. Inspect the mandrel periodically for thread wear, as a worn mandrel can cause inconsistent setting or insert spin-out. Replace worn mandrels promptly to maintain tool performance.