This precision-engineered adapter is crafted from high-quality steel ensuring durability and reliability in industrial applications. Designed to connect 9/16-18 male SAE O-Ring Boss threads to 3/8-18 male NPT threads it provides a secure and leak-resistant joint.
Manufactured by Brennan Industries Inc this adapter is suitable for use in various hydraulic and pneumatic systems. The robust construction is ideal for maintaining integrity under pressure making it an essential component in demanding environments.
This non-sealant adapter is designed with precise threading to ensure a tight fit eliminating the risk of fluid leakage and ensuring consistent performance. The catalog number for easy reference is C1EK74.
MPN: 6401-06-06-O
Supplier Part Number: 6401-06-06-O
Loading related products…
Specifications
Alternate Part Numbers
Alternate Part Number6401-06-06, Alternate Part Number C1EK74, Alternate Part Number MI-00318450, Alternate Part Number MINO-00028F65040
Brand
Brennan Industries Inc
Brand
Brennan Industries
Pack Size
1.00
UOM
EA
L
1.30
Supplier Part Number
6401-06-06-O
Thread 1
9/16-18
Thread 2
3/8-18
Thread Sealant
No
Product Weight
0.09 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 (1)
Question by: Brenda W on Jan 27, 2026, 10:13 AM
Will this adapter work for connecting a 9/16-18 male SAE O-ring to a 3/8-18 male NPT?
Answer by: Customer Support on Jan 28, 2026, 8:24 PM
Yes, that's exactly what it's designed for. It connects a 9/16-18 male SAE O-Ring Boss (Straight Thread O-Ring) to a 3/8-18 male NPT thread.
