Name: Brass Adapter Male 9/16"-18 to Female 3/8"-24
Brand: Inline Tube
SKU: AD3
Price: 9.50 USD
Availability: InStock

(800) 385-9452

Inline Tube’s Preformed Lines are your go-to for replacing worn-out lines on classic and late-model vehicles alike. Whether it’s brake, fuel, engine, or transmission cooler lines, our stainless steel, OE steel and nylon kits are designed to match factory specs, saving you time and hassle. Crafted with precision, these durable replacements fit a wide range of makes and models, ensuring reliable fluid flow and performance. From rusted-out classics to daily drivers needing a refresh, we’ve got the exact-fit parts to keep you rolling.

Inline Tube’s preformed replacement brake lines are engineered from factory original lines and CNC manufactured for precision. All lines are formed utilizing the correct automotive grade, OE or stainless steel tubing and includes the correct style flares and fittings along with the protective wrap, installed on the lines.

Inline Tube’s preformed replacement fuel lines are engineered from factory original lines and CNC manufactured for precision. All lines are formed utilizing the correct automotive grade, OE or stainless steel tubing in the correct diameter and includes the correct style flares, fittings and protective wrap, installed on the lines.

Inline Tube’s preformed replacement engine lines are engineered from factory original lines and CNC manufactured for precision. All lines are formed utilizing the correct automotive grade, OE or stainless steel tubing and includes the correct style flares and fittings where equipped on the lines.

Inline Tube’s preformed replacement transmission cooler and modulator vacuum lines are engineered from factory original lines and CNC manufactured for precision. All lines are formed utilizing the correct automotive grade, OE or stainless steel tubing and includes the correct style flares, fittings and protective wrap, installed on the lines.

Inline Tube’s nylon fuel line kits are engineered to be an easy fix for rusted out factory fuel lines. These kits have all the end fittings, tubing, and straps needed to repair your existing fuel lines and get your vehicle back on the road quickly.

Inline Tube’s replacement clip kits are engineered from factory original clips in the correct shape, style and thickness. All clip kits include all the brake or fuel line clips and mounting hardware needed per application.

Bring your classic car’s braking system back to life with Inline Tube’s brake products. Designed for restoration enthusiasts, this lineup covers everything from disc brake conversion kits to drum brake components, hoses, parking brake cables, and clips. Each part is crafted to OEM standards, offering stainless steel or rubber options where it counts, so your vintage ride stops as good as it looks. Whether you’re upgrading to modern discs or keeping the original drum vibe, our preformed and authentic pieces ensure a seamless fit for that factory-fresh feel.

Inline Tube’s disc brake conversions offer complete bolt on front and rear disc brake conversions as well as individual components. Our complete conversion kits come with every high quality part needed to upgrade to disc brakes. These same quality caliper brackets, master cylinders, as well as other parts are available separately.

Inline Tube carries all the components to get your drum brakes working like new again. We carry everything from the drums to the wheel cylinders, down to every piece to make the system complete. All pieces are available separate, or buy a kit that has it all.

Inline Tube stocks hundreds of OEM rubber flex hose applications. All rubber flex hoses are made to factory specifications and are identical to the originals. All hoses are in stock and ready to ship. If you are working on a concourse or factory restoration, these hoses will be a great compliment to Inline Tube's preformed brake line kit.

Inline Tube’s factory replacement brake components are the highest quality reproduction parts on the market. Our factory correct master cylinders, distribution blocks, valves and parts are all made to Inline Tube’s quality standard for factory performance and appearance.

Inline Tube’s factory correct parking brake cables are the highest quality reproduction cables on the market. Our factory correct parking brake cables are made with the correct metal housing, ball or barrel ends, and anchor points at the wheels, frame, and pedal. Whether it’s a maintenance replacement or a concourse restoration, Inline Tube’s Factory correct parking brakes are the market standard.

Inline Tube has reproduced over 80 different, hard to find, clips. All these clips are made identical to the factory originals with the correct thickness metal and the exact detail you have come to expect from Inline Tube products. All our clips are made to factory OEM specifications and come in many sizes, shapes and styles.

Inline Tube’s DIY & Street Rod products are built for the hands-on builder chasing a custom classic or a standout hot rod. From raw tubing and DIY plumbing kits to specialized tools, fittings, stainless braided hoses, and brake components, we’ve got what you need to craft something unique. Our parts blend restoration-grade quality with street rod flair— easy installs and durable materials for lasting performance.

Inline Tube’s DIY tubing is available in OE Steel, stainless, or copper nickel in lengths up to 25 feet. At Inline Tube we bend over a million feet of tube each year, this allows us to specify grade and softness of our tubing from the mill. This means you are getting softened easy to flare and bend tubing and not general off-the-shelf harder specification tube.

Inline Tube’s DIY plumbing kits are offered for factory systems as well as one-off street rods. All kits come with the necessary fittings, clamps, spring wrap, and hardware to plumb a complete brake line system. Inline Tube also offers DIY transmission and fuel plumbing kits.

Inline Tube’s DIY brake line tubing tools are the highest quality tools available. Whether you are a professional using the tools on a daily basis or a DIYer working on personal cars, these heavy duty flare tools, benders, and straighteners will help you get the job done right.

Inline Tube manufactures over 60 different fitting sizes in both color plated finishes and stainless steel varieties as well as AN fittings, hose fittings, adapters, tees and unions. We have everything you need to complete you DIY or Street Rod brake plumbing project.

Inline Tube’s Power Braid® stainless brake hoses can be made for any application. Whether you are doing a disc brake conversion or regular maintenance, Power Braid stainless hoses will increase your braking performance. All Power Braid hoses are available with a clear or black rubber coating.

Inline Tube’s DIY brake components will help you plumb your custom brake application. Here you can find residual pressure valves, small dual diaphragm brake boosters in chrome or black, adjustable or preset proportioning valves in brass or chrome, or master cylinders in chrome or black.

Inline Tube’s Restoration parts are a treasure trove for classic car restorers aiming to recapture that original glory. Covering suspension, engine, transmission, exhaust, body, firewall, interior, wheels, and more, our parts are designed to match vintage specs down to the last fastener. Add authentic decals, stencils, paint, or protective car covers, and you’ve got a full rebuild kit in one place. Each piece—from rugged underbody clips to showroom-ready interior details—brings precision and durability to your project.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The suspension and underbody category contains products and hardware for body mounts, control arms, sway bars, and tie rods.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The engine category contains products such as head bolts, pulleys, radiator hoses, return springs, and spark plug wire looms.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The transmission category contains mounts & hardware, back drive, automatic transmission, and manual transmission parts.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The exhaust category contains complete sets, hangers and clamps, head pipes, mufflers, manifold, and tail pipe.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The body category contains products such as fender and bumper brackets, exterior lighting, emblems, shims, and fuel tank parts.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The firewall and cowl category contains product such as cowl screens, firewall pads, heater delete plates, steering column plates, and windshield wiper parts.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The interior and trunk category contains products such as seat hardware, spare tire hardware, glove box, package tray, dash and door parts.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The wheels category contains center caps, hub caps, lug nuts, stencils, and trim rings.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. Here you will find individual head bolts, exhaust manifold bolts, and an assortment of other hardware.

Inline Tube’s restoration paints have been matched to the factory original colors using a state of the art spectrophotometer. The paint category contains engine paint, wheel paint, interior trunk paint, and primers.

Inline Tube’s restoration parts have been engineered from factory original parts and duplicated to exacting standards. The paperwork category contains assembly manuals, stampers, stencils, decals, and tags.

Inline Tube's plastic car cover are designed as an economical way to protect your car. These covers work great under your permanent car cover as an additional layer of protection against dirt and dust. These will also serve as temporary protection at outdoor car shows or cruises.

Preformed Lines

Brake Lines

Fuel Lines

Engine Lines

Transmission Lines

Nylon Fuel Lines

Vehicle Clip Sets
Brake Products

Disc Brake Conversion

Drum Brakes

Brake Hoses

Brake Components

Parking Brake Cables

Clips-Clamps
DIY & Street Rod

Tubing

DIY Plumbing Kits

Tools

Fittings-Adapters

Stainless Braided Hoses

DIY Brake Components
Restoration Parts

Suspension-Underbody

Engine

Transmission

Exhaust

Body

Firewall-Cowl

Interior-Trunk

Wheels

Individual Fasteners

Paint

Paperwork-Decals-Stencils

Plastic Car Covers
Catalogs
Support
Product Requests
Quick Order

Brass Adapter Male 9/16"-18 to Female 3/8"-24

Exclusions This product is not eligible for any discounts or promotions.

Material Brass

California Proposition 65 WARNING: This product may expose you to chemicals which are known to the state of California to cause cancer, birth defects, or other reproductive harm. For more information visit https://www.p65warnings.ca.gov/