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Steel Adapter, 1/4-18 Female NPT To 3/4-16 Male SAE O-Ring Boss (Straight Thread O-Ring), Straight

Description & Features

The Steel Adapter 1/4-18 Female NPT To 3/4-16 Male SAE O-Ring Boss (Straight Thread O-Ring) Straight offers a robust and reliable connection solution for industrial applications. Manufactured by Brennan Industries Inc this adapter ensures durability and high performance.

This adapter is designed with precision threading featuring a 1/4-18 Female NPT on one end and a 3/4-16 Male SAE O-Ring Boss (ORB) on the other. The straight design allows for straightforward installation and integration into existing systems ensuring leak-proof connections without the need for additional thread sealant.

Ideal for various industrial uses this connector meets rigorous quality standards offering a dependable transition between different thread types. The high-quality steel construction provides excellent resistance to wear and corrosion making it suitable for demanding environments.

Supplier Part Number: 6405-08-04-O

Specifications

A 1.16	Alternate Part Numbers Alternate Part Number 6405-08-04, Alternate Part Number A2216-4-8S, Alternate Part Number C1BX48, Alternate Part Number MI-00320214, Alternate Part Number MINO-00028F65788	Brand Brennan Industries Inc	Brand Brennan Industries	Pack Size 1.00	UOM EA	Supplier Part Number 6405-08-04-O	Thread 1 1/4-18	Thread 2 3/4-16	Thread Sealant No	Product Weight 0.12 lbs

Similar Products

Model Number	Thread 1	Thread 2	A
2216-12-12S Female NPT To Male ORB Adapter	3/4-14	1-1/16-12	1.67
2216-16-16S Female NPT To Male ORB Adapter	1-11-1/2	1-5/16-12	1.91
2216-2-4S Female NPT To Male ORB Adapter	1/8-27	7/16-20	0.92
2216-8-8S Female NPT To Male ORB Adapter	1/2-14	3/4-16	1.65
6405-24-20-O Female NPT To Male ORB Adapter	1-1/4-11-1/2	1-7/8-12	2.12
2216-12-16S Female NPT To Male ORB Adapter	3/4-14	1-5/16-12	1
2216-16-20S Female NPT To Male ORB Adapter	1-11-1/2	1-5/8-12	1
2216-20-20S Female NPT To Male ORB Adapter	1-1/4-11-1/2	1-5/8-12	2
2216-24-24S Female NPT To Male ORB Adapter	1-1/2-11-1/2	1-7/8-12	2
2216-4-5S Female NPT To Male ORB Adapter	1/4-18	1/2-20	1.2
2216-4-6S Female NPT To Male ORB Adapter	1/4-18	9/16-18	1.24
2216-6-12S Female NPT To Male ORB Adapter	3/8-18	1-1/16-12	1.34
2216-6-8S Female NPT To Male ORB Adapter	3/8-18	3/4-16	1.25
2216-8-10S Female NPT To Male ORB Adapter	1/2-14	7/8-14	1.54
2216-8-12S Female NPT To Male ORB Adapter	1/2-14	1-1/16-12	1.72
6405-04-04-O Female NPT To Male ORB Adapter	1/4-18	7/16-20	1.16
6405-04-06-O Female NPT To Male ORB Adapter	3/8-18	7/16-20	1.21
6405-05-02-O Female NPT To Male ORB Adapter	1/8-27	1/2-20	0.94
6405-06-06-O Female NPT To Male ORB Adapter	3/8-18	9/16-18	1.16
6405-06-08-O Female NPT To Male ORB Adapter	1/2-14	9/16-18	1.4
6405-08-04-O Female NPT To Male ORB Adapter	1/4-18	3/4-16	1.16
6405-10-04-O Female NPT To Male ORB Adapter	1/4-18	7/8-14	0.81
6405-10-06-O Female NPT To Male ORB Adapter	3/8-18	7/8-14	1.55
6405-12-16-O Female NPT To Male ORB Adapter	1-11-1/2	1-1/16-12	1.91
6405-16-08-O Female NPT To Male ORB Adapter	1/2-14	1-5/16-12	1.61
6405-20-12-O Female NPT To Male ORB Adapter	3/4-14	1-5/8-12	1.19
6405-24-16-O Female NPT To Male ORB Adapter	1-11-1/2	1-7/8-12	1

Product Questions & Answers (2)

Question by: Hank A on Oct 8, 2025, 11:00 AM

Will this here adapter work to hook up a pressure gauge with a female NPT fitting to a hydraulic pump with a SAE O-ring boss?

Answer by: Customer Support on Oct 10, 2025, 8:20 AM

This adapter is indeed designed for that purpose, providing a transition from a 1/4-18 female NPT to a 3/4-16 male SAE O-ring boss.

Question by: Tony F on Sep 19, 2025, 12:21 PM

got a line running 1/4 NPT female port and need to tie into a 3/4-16 ORB fitting, this the right piece for that?

Answer by: Customer Support on Sep 20, 2025, 4:26 PM

That's what this adapter is built for. One end is 1/4-18 Female NPT, the other is 3/4-16 Male SAE O-Ring Boss. Straight configuration, so no angle to account for during install. The ORB end seals with an o-ring against a boss port, which keeps things tight without needing thread tape or sealant on that side. The NPT end is a standard pipe thread connection. If your ports match those two thread specs, this will bridge them cleanly.