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#4 MP X #12 FP

Description & Features

This straight steel expander features a #4 MP x #12 FP connection. The #4 MP X #12 FP adapter is constructed from quality steel to ensure a secure, leak-proof connection in demanding hydraulic applications. This fitting has a male NPTF 1/4-18 thread and a female NPTF 3/4-14 thread, both manufactured to SAE J476 specifications.

With a maximum dynamic pressure of 4,000 PSI, this expander fitting is suitable for high-pressure environments.

SKU: 5405-04-12

Supplier Part Number (MPN): 5405-04-12

Alternate Part Numbers: A2040-4-12S

Specifications

Brand Brennan Industries Inc	Brand Brennan Industries	Pack Size 1.00	UOM EA	Supplier Part Number 5405-04-12	Product Weight 0.25 lbs

Product Questions & Answers (2)

Question by: Travis C on Jun 18, 2025, 8:43 AM

trying to step up from a 1/4 pipe male to a 3/4 female port. is that what this fitting does?

Answer by: Customer Support on Jun 19, 2025, 8:53 AM

Function-wise, it is a straight steel expander with a male NPTF 1/4-18 on one end and a female NPTF 3/4-14 on the other, so it adapts a smaller male pipe thread into a larger female pipe thread.

Question by: Warren M on Nov 28, 2025, 8:17 PM

fitting's rated to 4,000 PSI -- that enough for most standard hydraulic lines or is that on the lower end of what folks typically run?

Answer by: Customer Support on Nov 30, 2025, 12:58 PM

4,000 PSI dynamic pressure covers a wide range of common hydraulic circuits, including most ag equipment, skid steers, and general industrial lines. It's not on the low end by any stretch. Where you'd start bumping into limits is with high-performance systems running sustained peak pressures above that threshold, but for everyday hydraulic work, this fitting holds up fine.