Menu

Shop

Garage

Cart

Account

Products to Compare (max of 3)
X
Compare These Parts

Automotive Fittings | IFF, IFM, AN, & NPT

6/7/2021
Add Article To List
Brake Plumbing Basics
IFF and IFM

These are some common terms used in the industry when discussing brake fittings. IFF - meaning “Inverted Flare Female” and IFM - meaning “Inverted Flare Male”. The diagram to the right illustrates the two most common types of fittings used in a typical Street Rod brake system. The first is the inverted double flare, used by most domestic production cars and trucks. It uses a 45* double flare to seal, which has tubing that is folded over into itself before flaring outward. On the right, is a 37* single flared line with a tube sleeve and coupler that allows you to adapt to AN fittings.

3/16-inch tubing is one of the most common sizes used in brake systems, which makes use of a 3/8-24 inverted flare nut like part number 91031820. When using 1/4-inch brake tubing, a 7/16-24 inverted flare nut is used, like part number 91031819.

AN Fittings

AN fittings, also known as Army/Navy, were originally developed as a military standard that dates back as early as World War II. A fitting listed at – 3 (dash three) refers to the inside diameter of the fitting, for instance a – 3 AN would fit a metal tube outside diameter of 3/16-inch. You will also notice that the size increments are 1/16-inch apart. All of the AN fittings that Speedway offers will feature a 37* tapered flare. The chart to the right and below will show some of the common AN sizes along with the closest national pipe thread size (NPT). Note that AN fittings and NPT fittings will not work together.

NPT

National Pipe Thread is a tapered machine thread for threaded pipes and fittings . NPT threads can be referred to as “Male pipe thread” or “Female pipe thread”. This common thread can be found on a wide variety of applications from natural gas pipes, plumbing fixtures, hydraulic lines and hoses, and even your car. We use these in the Street Rod and Racing industries for fluid fittings such as oil lines, brake lines, and coolant lines. NPT threads are tapered to create an interference fit and often use thread tape or thread sealant to form a liquid tight seal without the use of crush washers, O-rings or gaskets. NPT fitting sizing does not refer to the physical dimension of the threads. The sizing chart is in reference to the inside diameter of a schedule 40 black iron pipe. Example: a ½ NPT thread has an outside diameter of approximately .840” (at the small end of the tapered thread).

Products Featured in this Article

Related Articles

Quick Tip on Securing AN Fittings
by Outside Author - Posted in Tech
2/24/2017
Dick from Koul Tools shares a tip on how to properly seat the AN fittings using the Koul Tools device.
Using Koul Tools For Easy AN Hose Assembly
by Speedway Tech Team - Posted in Tech
9/21/2016
Learn how to use Koul Tools for your AN Hose Assembly with our video guide. Koul Tools make it easy to install a braided rubber hose into the AN fitting socket.
Oil Pressure & Water Temp Gauges
by Charles Aman - Posted in Tech
8/30/2018
How to prevent blowing a motor by keeping up with you weekly maintenance routine. Charles reviews how to install oil pressure and water temperature gauges to help prevent issues while racing.
Selecting An Electric Fuel Pump Over Mechanical
by Matthew McClure - Posted in Tech
3/6/2018
For most, an electric fuel pump can be a choice of form over function, but for others, it may be the best option. In this article, you will learn the advantages of using an electric fuel pump and how to install it in your car.
Hose & Fitting
by Speedway Tech Team - Posted in Tech
9/19/2016
Hose & Fitting
How to Build Push-On Hose Ends
by Speedway Tech Team - Posted in Tech
7/1/2016
Learn how to assemble AN push-on hose ends the right way. It sounds simple enough, but doing this wrong can cause all number of issues down the road.
Truck Arm Suspension Design: 67-72 C10 Suspension Upgrades
by Joe McCollough - Posted in Tech
9/12/2022
In this Tech Talk episode, we detail the install of a C10 G-Comp Rear Suspension kit. This kit uses truck arms like the original, but adds coilovers and plenty of adjustment options.
How to C-Notch a C10 Truck Frame
by Joe McCollough - Posted in Tech
9/12/2022
Follow along as we give our C10 truck project a much needed dose of suspension travel with a bolt-on C-notch kit.
How to Convert Rear Drum Brakes to Disc Brakes (Install & Adjustment)
by Joe McCollough - Posted in Tech
6/7/2022
In this video, we walk through the process of installing a rear disc brake conversion kit that uses a weld-on caliper bracket.
Using GoJak Wheel Dollies to Easily Move Your Vehicle
by Mark Houlahan - Posted in Videos
6/6/2022
The GoJak wheel dolly makes moving immobile vehicles around your shop easy as place, pump, and push! Watch the video for all the details and you'll wonder why your shop hasn't had a set sooner!
Error
X
Note
X
Ok