Midland Industries SS6408-HH-04 Hollow Hex Plug 1/4 in Orb

Product Description

The MIDLAND INDUSTRIES SS6408-HH-04 is a hollow hex plug designed for SAE O-Ring Boss (ORB) port applications. It features a 1/4-inch male O-Ring Boss connection and is machined from 316 stainless steel for strong corrosion resistance in demanding fluid and gas system environments. The plug measures 0.468 inches in length, uses a 7/16-20 thread, and accepts a 3/16-inch hex key for installation. Rated for operating temperatures up to 1000 degrees F, this fitting is suited for high-temperature hydraulic, pneumatic, and process piping systems. Licensed plumbers, pipefitters, and hydraulic system technicians are the primary installers.

This hollow hex plug fits into SAE O-Ring Boss ports to cap or close off a port while maintaining a leak-resistant seal through the O-Ring face. It is used in both residential and commercial fluid power, hydraulic, and industrial process piping systems where stainless steel construction is required for corrosion resistance or sanitary compliance. The SS6408-HH-04 is part of the SS6408-HHP series of O-Ring hollow hex plugs and is cataloged under the SS SAE O-Ring Adapters section.

Key Features

• 316 stainless steel construction provides excellent corrosion resistance for harsh fluid and chemical environments
• 1/4-inch male O-Ring Boss connection delivers a reliable, leak-resistant seal at the port face
• Rated to 1000 degrees F operating temperature for use in high-temperature system applications
• Compact 0.468-inch length fits into tight port locations without interference
• 3/16-inch hex drive allows installation with standard hex key tooling
• 7/16-20 thread specification ensures precise fitment in SAE ORB ported components

Compatibility

Designed as an OEM-style replacement or service fitting for hydraulic, pneumatic, and process piping components with 1/4-inch SAE O-Ring Boss ports requiring a stainless steel hollow hex plug.

Installation Notes

Installation is performed by licensed plumbers, pipefitters, or hydraulic system technicians. Depressurize and isolate the system completely before removing or installing any port plug. Use a calibrated torque wrench with the appropriate 3/16-inch hex bit and follow SAE or system manufacturer torque guidelines for ORB fittings. Inspect the O-Ring sealing surface for nicks or contamination before seating the plug to ensure a leak-free connection.