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Steel Adapter, 3/8-18 Male NPT To 7/16-20 Female SAE O-Ring Boss (Straight Thread O-Ring), Straight

Description & Features

Engineered for industrial applications, the Brennan Industries Inc Male NPT to Female ORB Adapter 6404-04-06 ensures precise connections between 3/8-18 NPT and 7/16-20 SAE O-Ring Boss threads.

Constructed from high-quality steel, this adapter is designed for robustness and longevity. It features a straight thread configuration, making it suitable for various pressure-related environments.

This adapter facilitates a secure and reliable seal without requiring additional thread sealant. Its design caters to systems needing consistent and leak-proof connectivity.

The specific threading, 3/8-18 on one end and 7/16-20 on the other, provides compatibility and versatility in industrial settings.

MPN: 6404-04-06

Supplier Part Number: 6404-04-06

Specifications

A 1.13	Alternate Part Numbers Alternate Part Number A2246-6-4S, Alternate Part Number C1BX31, Alternate Part Number MI-02144119, Alternate Part Number MINO-00028J33611	Brand Brennan Industries Inc	Brand Brennan Industries	Pack Size 1.00	UOM EA	Supplier Part Number 6404-04-06	Thread 1 3/8-18	Thread 2 7/16-20	Thread Sealant No	Product Weight 0.08 lbs

Similar Products

Model Number	Thread 1	Thread 2	A
2246-4-6S Male NPT To Female ORB Adapter	1/4-18	9/16-18	1.36
2246-6-8S Male NPT To Female ORB Adapter	3/8-18	3/4-16	1.45
6404-04-04 Male NPT To Female ORB Adapter	1/4-18	7/16-20	1.32
2246-12-12S Male NPT To Female ORB Adapter	3/4-14	1-1/16-12	1.92
2246-16-16S Male NPT To Female ORB Adapter	1-11-1/2	1-5/16-12	1.91
2246-2-4S Male NPT To Female ORB Adapter	1/8-27	7/16-20	1.09
2246-8-10S Male NPT To Female ORB Adapter	1/2-14	7/8-14	1.78
6404-04-06 Male NPT To Female ORB Adapter	3/8-18	7/16-20	1.13
6404-05-04 Male NPT To Female ORB Adapter	1/2-20	7/16-20	1.39
6404-06-06 Male NPT To Female ORB Adapter	3/8-18	9/16-18	1.39
6404-08-08 Male NPT To Female ORB Adapter	1/2-14	3/4-16	1.7

Product Questions & Answers (3)

Question by: Ricky C on Nov 6, 2025, 3:53 PM

trying to hook a 3/8-18 npt port up to an ORB line, is this the right adapter?

Answer by: Customer Support on Nov 8, 2025, 6:33 AM

For that mix of threads, it matches what you described. One side is 3/8-18 male NPT, and the other side is 7/16-20 female SAE O-Ring Boss, straight thread.

Question by: Duane R on Dec 10, 2025, 12:58 PM

got a hydraulic line running NPT fittings and need to tie into a port that's SAE O-ring boss, will this adapter bridge that gap without needing any thread tape or sealant?

Answer by: Customer Support on Dec 12, 2025, 10:54 AM

That's what this one's built for. The male end threads in as 3/8-18 NPT, and the female side accepts 7/16-20 SAE O-Ring Boss straight thread. The ORB end gets its seal from the O-ring itself, so no tape or thread sealant is needed on that side. Just make sure your NPT end is sealed properly, since tapered pipe threads typically do benefit from some sealant or tape on the male threads.

Question by: Duane A on Jul 12, 2025, 9:17 AM

So this adapter, it's steel right? Just making sure it can handle what I'm throwin' at it.

Answer by: Customer Support on Jul 14, 2025, 7:34 AM

it's made from high-quality steel, so it's built to be durable for industrial use.