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Steel Adapter, 3/4-16 Male SAE O-Ring Boss (Straight Thread O-Ring) To 3/4-14 Male NPT, Straight

Alternate Part Numbers Alternate Part Number 6401-08-12, Alternate Part Number C1DY20, Alternate Part Number C1EK78, Alternate Part Number MI-00445148, Alternate Part Number MINO-00028I01844	Brand Brennan Industries Inc	Brand Brennan Industries	Pack Size 1.00	UOM EA	L 1.59	Supplier Part Number 6401-08-12-O	Thread 1 3/4-16	Thread 2 3/4-14	Thread Sealant No	Product Weight 0.23 lbs

Product Questions & Answers 2

Product Questions & Answers

So this'll go from a pipe thread to a straight thread with an O-ring, right? Just wanna make sure I'm gettin' the right thing.

Question by: Janice D on Feb 8, 2026, 9:53 AM

Exactly. This steel adapter converts from a 3/4-14 male NPT (pipe thread) to a 3/4-16 male SAE O-ring boss (straight thread O-ring).

Answer by: Customer Support on Feb 9, 2026, 11:17 AM

got a hose end with 3/4-16 ORB on it and my port is 3/4-14 NPT. is this the right adapter to tie those together?

Question by: Gene W on Dec 30, 2025, 1:49 PM

It bridges a 3/4-16 male SAE O-ring boss connection over to a 3/4-14 male NPT connection, straight style. If those are the two thread types and sizes you are trying to join, this adapter matches that ORB-to-NPT combination.

Answer by: Customer Support on Jan 1, 2026, 9:25 AM

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Model Number	Thread 1	Thread 2	L
6401-08-06-O	3/4-16	3/8-18	1.36
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6401-08-12-O	3/4-16	3/4-14	1.59
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6401-10-08-O	7/8-14	1/2-14	1.69
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6401-04-02-O	7/16-20	1/8-27	1.07
6401-06-02-O	9/16-18	1/8-27	1.11
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6401-06-06-O	9/16-18	3/8-18	1.3
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6401-20-20-O	1-5/8-12	1-1/4-11-1/2	2.17