Custom adapters
Inverted flare (INV) to NPT adapters, machined to order
One machined part that connects SAE inverted flare (INV) to NPT in the exact sizes you need, instead of a stack of off the shelf adapters. Pick the shape, material and finish, see the price as you go, and get it in 2 weeks.
Common sizes
Straight adapters in 303 stainless, priced each at 10 pieces. Any size is available on either end, and you can change the shape, length, bore and material in the builder.
| Inverted flare (INV) end | NPT end | Rated to | Each at 10 | |
|---|---|---|---|---|
| 5/16-28 INV female, 1/8 in line | 1/16 NPT male | 2,800 psi | $40.01 | Build this |
| 3/8-24 INV female, 3/16 in line | 1/8 NPT male | 1,900 psi | $40.01 | Build this |
| 7/16-24 INV female, 1/4 in line | 1/8 NPT male | 1,400 psi | $40.01 | Build this |
| 7/16-24 INV female, 1/4 in line | 1/4 NPT male | 1,400 psi | $40.01 | Build this |
| 1/2-20 INV female, 5/16 in line | 3/8 NPT male | 1,200 psi | $40.01 | Build this |
| 5/8-18 INV female, 3/8 in line | 3/8 NPT male | 1,000 psi | $40.01 | Build this |
| 11/16-18 INV female, 7/16 in line | 1/2 NPT male | 750 psi | $40.01 | Build this |
| 3/4-18 INV female, 1/2 in line | 1/2 NPT male | 750 psi | $40.01 | Build this |
| 7/8-18 INV female, 5/8 in line | 3/4 NPT male | 650 psi | $40.01 | Build this |
| 1 1/16-16 INV female, 3/4 in line | 3/4 NPT male | 550 psi | $40.01 | Build this |
Ratings are for 303 stainless at room temperature, limited by the lower rated end. Single parts start at $120.
About Inverted flare (INV)
A 45° flared tube clamped against a 42° seat inside the port by a tube nut. Brake and fuel catalogs write it INV, as in 3/8-24 INV for 3/16 in line. The seat is protected inside the fitting, which is why it is used on brake, fuel, transmission and power steering lines. Working pressure falls as the tube gets larger, from 2,800 psi at 1/8 in to 550 psi at 3/4 in with copper tube.
SAE J512 inverted flare (INV). Seals by: 45° flared tube clamped on a 42° seat inside the port.
About NPT
American tapered pipe thread. The taper wedges tight and seals on the thread flanks with sealant or PTFE tape. Found on pumps, compressors, gauges, valves and general plumbing across North America.
ASME B1.20.1. Seals by: taper, sealant or ptfe tape.
One part, fewer leaks
A single machined adapter replaces a stack of two or three, so there are fewer joints to leak and the run is shorter and lighter.
Any shape
Straight, 45°, 90°, street 90, tee, Y, cross or a manifold with up to 8 outlets. Stainless, steel, brass, aluminum or engineering plastics.
Checked before it ships
Threads are checked with go and no-go gauges and every order ships with a certificate of conformance. Pressure test reports on request.
Questions
What pressure is a Inverted flare (INV) to NPT adapter rated for?
It depends on the size and material. In 303 stainless, the common sizes on this page are rated from 550 to 2,800 psi, set by the lower rated end. The builder shows the exact rating for your part, including a wall thickness check.
Can I get a Inverted flare (INV) to NPT adapter as an elbow or tee?
Yes. Choose straight, 45°, 90°, street 90, tee, cross or a manifold, then set the length, bore, material and finish. The price and pressure rating update as you design.
How many do I have to order?
There is no minimum. Single parts start at $120, pairs at $55 each, and the price per part drops as quantity goes up.
How fast will it ship?
Standard orders ship in 2 weeks. 1 week and 3 day delivery are available. Every thread is gauged, and every order ships with a certificate of conformance.
Related adapters
Need a size or shape not listed?
Every combination of 29 standards is available in the builder.
Open the builder