Part Number: 6409-SS

SAE ORB Hex Socket Plug (Stainless Steel)

Product Overview

The Delphi Fittings Part 6409-SS is an SAE O-Ring Boss (ORB) Hex Socket Plug, precision-manufactured from high-quality stainless steel (typically Grade 316 SS). This plug is engineered to provide a secure and effective seal for unused female ORB ports in hydraulic systems. Its key feature is an internal hexagonal (Allen) drive, which allows for a flush or low-profile installation, making it ideal for applications with space constraints or where a smooth external surface is desired. The plug includes a male SAE O-Ring Boss thread and an O-ring groove for the sealing element. The stainless steel construction ensures superior corrosion resistance, rendering it indispensable for use in harsh environments such as marine applications, chemical processing plants, food and beverage facilities, or any system where material integrity and resistance to corrosive media are critical.

Key Features & Specifications

Material	High-Grade Stainless Steel (Typically 316 SS for maximum corrosion resistance)
Configuration	Male SAE O-Ring Boss (ORB) Plug (thread and O-ring groove dimensions conforming to SAE J1926-1 / ISO 11926-1)
Head Style	Internal Hexagonal Socket (Allen Drive) for flush or recessed installation using a hex key.
Sealing Mechanism	Utilizes an elastomeric O-ring (seated in the groove on the plug body) which compresses against the chamfered boss of the female ORB port to create a highly reliable, leak-proof seal.
Corrosion Protection	Inherent to the stainless steel material; may also be passivated to further enhance surface integrity and corrosion resistance.
Primary Function	To securely seal and close off unused female SAE O-Ring Boss ports in hydraulic systems, particularly in stainless steel systems or corrosive environments, while providing a flush or low-profile finish.
Working Pressure	Designed to safely withstand the pressure ratings of the corresponding female ORB ports. Specific ratings are dependent on the size of the plug.
O-Ring Material	Viton® (FKM) is strongly recommended for stainless steel applications to ensure broad chemical compatibility and performance across a wide temperature range. The O-ring is typically supplied with the plug.

Commonly Available Sizes (Part #6409-SS Series)

Delphi Fittings offers the Stainless Steel SAE ORB Hex Socket Plug in a comprehensive range of sizes, denoted by the ORB dash number, which corresponds to the female ORB port it is designed to seal.

Examples include (ORB Plug Size):

6409-02-SS: For -02 (5/16-24 UNF) ORB Port
6409-03-SS: For -03 (3/8-24 UNF) ORB Port
6409-04-SS: For -04 (7/16-20 UNF) ORB Port
6409-06-SS: For -06 (9/16-18 UNF) ORB Port
6409-08-SS: For -08 (3/4-16 UNF) ORB Port
6409-10-SS: For -10 (7/8-14 UNF) ORB Port
6409-12-SS: For -12 (1-1/16-12 UNF) ORB Port
6409-16-SS: For -16 (1-5/16-12 UNF) ORB Port
6409-20-SS: For -20 (1-5/8-12 UNF) ORB Port
6409-24-SS: For -24 (1-7/8-12 UNF) ORB Port

Note: Each plug includes an appropriate O-ring (Viton® recommended for stainless steel applications). For unlisted sizes or specific requirements, please contact our sales team.

Applications

The Part 6409-SS Stainless Steel ORB Hex Socket Plug is essential for:

Securely sealing unused SAE O-Ring Boss ports where a flush or low-profile installation is desired to avoid protrusions, common in applications with tight space constraints or for aesthetic reasons within stainless steel systems.
Preventing contamination and leakage from open hydraulic circuit ports during system maintenance, modification, storage, or when certain functionalities are not active.
Critical applications in industries such as marine and offshore, chemical processing, food and beverage production, pharmaceutical manufacturing, and any area where exposure to corrosive substances, saltwater, or stringent hygiene standards necessitates the use of stainless steel.
Maintaining system integrity and safety by ensuring all unused ORB ports are properly and durably sealed.

Installation & Usage Guidelines

Ensure the female ORB port to be sealed and the Part 6409-SS plug (including its threads, O-ring groove, and O-ring) are meticulously clean, undamaged, and entirely free from any contaminants or debris.
Verify that the O-ring material (Viton® is recommended for stainless steel and demanding applications) is correct for the specific system fluid, temperature, and pressure. Ensure the O-ring is correctly lubricated with a system-compatible fluid or an appropriate O-ring lubricant.
Carefully install the lubricated O-ring onto the plug, ensuring it is properly and evenly seated in its groove without being twisted, cut, or pinched.
Thread the ORB plug into the female ORB port by hand until the O-ring makes initial contact with the port's chamfer and the plug shoulder (if the design includes one) seats against the port face.
Use an appropriately sized Allen key (hexagonal wrench) inserted into the internal hex socket of the plug to tighten it to the manufacturer's recommended torque specification for the specific ORB size and stainless steel material. This ensures correct O-ring compression and a secure, leak-proof seal.
When working with stainless steel fittings, applying a suitable thread lubricant or anti-seize compound (compatible with stainless steel) to the plug threads is crucial to prevent galling during assembly and allow for easier removal if necessary in the future.

Why Choose Delphi Fittings Part 6409-SS?

Flush and Low-Profile Installation: The internal hexagonal socket drive allows the plug to be installed flush with or recessed into the port surface, ideal for applications with space limitations or where a smooth external profile is preferred.
Superior Corrosion Resistance: Manufactured from high-grade stainless steel (typically 316 SS), offering maximum durability and longevity in harsh chemical, marine, or high-humidity environments.
High-Integrity ORB Sealing: Utilizes the industry-proven SAE O-Ring Boss sealing mechanism, ensuring a reliable, leak-proof closure of unused hydraulic ports even under high pressure.
Effective System Protection: Prevents contamination of the hydraulic system and loss of fluid from open ORB ports.
Full Adherence to Industry Standards: Meets SAE J1926 (ORB) specifications for thread and port compatibility, ensuring proper fit and function.
Quality-Assured Manufacturing: Produced under Delphi Fittings' rigorous ISO 9001:2015 certified quality management system, guaranteeing consistent high quality and dependable performance.

Get a Quote for Part 6409-SS - Stainless Steel SAE ORB Hex Socket Plug

For a secure, corrosion-resistant, and flush-fitting seal for unused female ORB ports in your critical hydraulic systems, the Part 6409-SS stainless steel hex socket plug is an ideal and discreet solution. Contact Delphi Fittings today for wholesale pricing, bulk order information, and expert technical support.

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