The steel adapter ensures reliable connection from a 3/4-16 male SAE O-ring boss (straight thread O-ring) to a 3/8-18 male NPT, maintaining consistent performance in industrial applications. Engineered with precision, it delivers exceptional durability and secure fittings.
Manufactured by Brennan Industries Inc, this component is designed to meet the rigorous demands of various industries, providing long-lasting usage. The adapter stands out for its robust construction, ensuring optimal sealing without requiring additional thread sealants.
This product is ideal for projects requiring a connection between ORB and NPT threads, serving primarily in the manufacturing and mechanical sectors. Its straightforward, dependable design makes it a staple for professionals seeking efficiency and reliability in their connections.
MPN: C1EK28
Supplier Part Number: 6401-08-06-O
Loading related products…
Specifications
Alternate Part Numbers
Alternate Part Number6401-08-06, Alternate Part Number C1EK28
Brand
Brennan Industries Inc
Brand
Brennan Industries
Pack Size
1.00
UOM
EA
L
1.36
Supplier Part Number
6401-08-06-O
Thread 1
3/4-16
Thread 2
3/8-18
Thread Sealant
No
Product Weight
0.12 lbs
Similar Products
Model Number
Thread 1
Thread 2
L
Price
Action
6401-08-06-OSteel Male ORB To NPT Adapter
3/4-16
3/8-18
1.36
6401-08-08-OSteel Male ORB To NPT Adapter
3/4-16
1/2-14
1.55
6401-08-12-OSteel Male ORB To NPT Adapter
3/4-16
3/4-14
1.59
6401-10-06-OSteel Male ORB To NPT Adapter
7/8-14
3/8-18
1.56
6401-10-08-OSteel Male ORB To NPT Adapter
7/8-14
1/2-14
1.69
6401-12-08-OSteel Male ORB To NPT Adapter
1-1/16-12
1/2-14
1.84
6401-12-12-OSteel Male ORB To NPT Adapter
1-1/16-12
3/4-14
1.73
6401-04-02-OSteel Male ORB To NPT Adapter
7/16-20
1/8-27
1.07
6401-06-02-OSteel Male ORB To NPT Adapter
9/16-18
1/8-27
1.11
6401-06-04-OSteel Male ORB To NPT Adapter
9/16-18
1/4-18
1.29
6401-06-06-OSteel Male ORB To NPT Adapter
9/16-18
3/8-18
1.3
6401-06-08-OSteel Male ORB To NPT Adapter
9/16-18
1/2-14
1.39
6401-08-04-OSteel Male ORB To NPT Adapter
3/4-16
1/4-18
1.24
6401-10-12-OSteel Male ORB To NPT Adapter
7/8-14
3/4-14
1.77
6401-16-16-OSteel Male ORB To NPT Adapter
1-5/16-12
1-11-1/2
1.9
6401-20-20-OSteel Male ORB To NPT Adapter
1-5/8-12
1-1/4-11-1/2
2.17
Product Questions & Answers (3)
Question by: Ricky R on Oct 6, 2025, 10:31 AM
got a hydraulic line coming off a pump with 3/8 NPT male on one end and need to tie into a port that's 3/4-16 straight thread o-ring boss. this the right piece for that?
Answer by: Customer Support on Oct 7, 2025, 11:44 AM
That's what this adapter is built for. One end is 3/4-16 Male SAE O-Ring Boss, the other is 3/8-18 Male NPT, and it runs straight through with no offset. So if your port takes a straight thread o-ring boss fitting and your line terminates in NPT male, this bridges that gap without needing additional pieces in between.
Question by: Judy G on Aug 5, 2025, 6:33 PM
trying to replace a fitting on my hose, is this the one that goes from 3/4-16 ORB male to 3/8-18 NPT male, straight?
Answer by: Customer Support on Aug 7, 2025, 6:56 AM
Match up the thread callouts and ends. This adapter is a straight steel fitting with a 3/4-16 male SAE O-Ring Boss on one side and a 3/8-18 male NPT on the other, so it fits that exact ORB-to-NPT male-to-male connection.
Question by: Cheryl F on Feb 3, 2026, 8:36 PM
got a hose end thats 3/4-16 ORB and my port is 3/8-18 npt, is this the right little adapter to tie em together
Answer by: Customer Support on Feb 5, 2026, 5:27 PM
Function-wise, yes. It is a straight steel adapter that goes from a 3/4-16 male SAE O-ring boss thread on one side to a 3/8-18 male NPT thread on the other.
