Best Brake Line Flaring Tool Kit for Stainless Steel (2026)

A rusted brake line always picks the worst moment to leak, and the fix starts with a clean flare on a fresh piece of tubing. Stainless steel holds up against rust, but it is harder than copper and less forgiving of a sloppy flare, so the tool matters. This guide to the best brake line flaring tool kit for stainless steel compares the kits by the flares they make, the sizes they fit, whether the listing states stainless steel, and what comes in the box.

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Picks for the garage

#	Product	Shop Score	Buy
1	LainKeen Brake Line Flaring Tool Kit for 45 and 37	9.7/10	Buy on Amazon
2	Fanmoss Brake Line Flaring Tool Kit	9.6/10	Buy on Amazon
3	Ailbiuko 3/16" 1/4" Professional Brake Line Repair	9.6/10	Buy on Amazon
4	NOLTHKAEL Brake Line Flaring Tool Kit	9.5/10	Buy on Amazon
5	Capri Tools 3/16 in. Double Flaring Tool Kit	9.4/10	Buy on Amazon

1

LainKeen Brake Line Flaring Tool Kit for 45 and 37

LainKeen·9.7/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A brake line flaring tool kit for 37 and 45 degree single, double and bubble flares on steel, stainless steel and soft metal tubing in 3/16, 1/4, 5/16 and 3/8 in sizes, with a 1 year warranty.

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Pros

• 37 and 45 degree flares in one kit
• States stainless steel, steel and soft metal
• Fits 3/16, 1/4, 5/16 and 3/8 in tubing
• 1 year warranty

Cons

• No tubing or fittings included
• Vise mount design, so it needs a vise
• No weight stated in the listing
• No cutter or bender included

2

Fanmoss Brake Line Flaring Tool Kit

Fanmoss·9.6/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A brake line flaring tool kit for 45 degree single, double and bubble flares on 304 stainless steel and steel tubing in 3/16, 1/4, 5/16 and 3/8 in sizes, with a 6 month warranty.

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Pros

• States 304 stainless steel and steel tubing
• 6 in T-handle screw clamp holds the die and tube
• Fits 3/16, 1/4, 5/16 and 3/8 in tubing
• 6 month warranty

Cons

• Not for under-car use
• No tubing or fittings included
• No weight stated in the listing
• Needs a bench-mounted or hitch-mounted vise

3

Ailbiuko 3/16" 1/4" Professional Brake Line Repair

Ailbiuko·9.6/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A complete brake line repair kit with a flaring tool for 45 degree single, double and bubble flares on 304 stainless steel, plus 2 x 25 ft tubing, 100 fittings, a bender and a cutter.

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Pros

• States 304 stainless steel, steel and soft metal
• Includes 2 x 25 ft tubing and 100 fittings
• Bender and cutter included
• Flaring tool fits 3/16, 1/4, 5/16 and 3/8 in lines

Cons

• No warranty term stated
• Tool must be used with a vise, bench only
• No weight stated in the listing
• Fittings use 4 thread sizes, so match them to your line

4

NOLTHKAEL Brake Line Flaring Tool Kit

NOLTHKAEL·9.5/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A brake line flaring kit with a 45 degree SAE flaring tool for 3/16 and 1/4 in tubing, 2 x 25 ft tube, 58 fittings, a tube bender and a tubing cutter.

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Pros

• Includes 2 x 25 ft tubing and 58 fittings
• Bender and tubing cutter included
• 45 degree single, double and bubble flares
• High-strength carbon steel tool with hardened components

Cons

• No stainless steel use stated in the listing
• Warranty description states no warranty
• Fits 3/16 and 1/4 in tubing only
• No weight stated in the listing

5

Capri Tools 3/16 in. Double Flaring Tool Kit

Capri Tools·9.4/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A compact 3/16 in. double flaring tool kit for 45 degree SAE double flares, with a mini tube cutter, tube bender and 10 mm and 17 mm combination wrenches, at 2.05 lb.

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Pros

• Works on the vehicle and off the vehicle
• Compact and portable at 2.05 lb
• Includes cutter, bender and 10 mm and 17 mm wrenches
• Detachable die also works with a bench vise

Cons

• States non-stainless steel tubing only
• Double flares only, no single or bubble flare
• Fits 3/16 in. tubing only
• No warranty term stated

Compared on paper

Specs such as CFM, PSI and torque are the manufacturer’s ratings as listed, collected 11 November 2026. A warranty term is stated for the LainKeen and Fanmoss kits, and none of the listings states an electrical listing, so safety scores zero across the picks.

How the points were given

Each kit is scored on performance, build, value, safety and warranty, using only what the listing publishes. The weights are on our How We Pick page.

Shop Scores range from a low of 9.2 to a high of 9.8, with each tool positioned by its weighted points proportionally, and more points always yields a higher score. Only powered tools, or tools with stated safety features, get safety points. Everything else is rated out of 90.

What the listings tell you

The LainKeen, Fanmoss and Ailbiuko listings state stainless steel, while the NOLTHKAEL listing names copper, aluminum and nickel-copper tubing, and the Capri listing states non-stainless steel. The LainKeen kit is the only pick that states both 37 and 45 degree flares. The Ailbiuko and NOLTHKAEL kits include tubing and fittings, while the Fanmoss and LainKeen kits are tool kits, and the Capri box adds a cutter, a bender and wrenches.

Buying guide: choosing the best brake line flaring tool kit for stainless steel

Stainless steel first

For stainless steel, read the materials list before anything else. The LainKeen listing states steel, stainless steel and soft metal, and the Fanmoss and Ailbiuko listings name 304 stainless steel. The NOLTHKAEL listing names copper, aluminum and nickel-copper tubing, and the Capri listing states non-stainless steel, so those two do not state stainless use. A kit that never names stainless steel is the wrong pick for this job.

Single, double or bubble

Brake lines use 45 degree single, double and bubble flares, and the LainKeen kit also makes 37 degree flares. The Ailbiuko listing spells out the steps: a single flare uses OP.0 then OP.2, a bubble flare uses OP.0 then OP.1, and a double flare uses OP.0, then OP.1, then OP.2. The Capri kit makes double flares only, so check the flare your fitting needs before you buy.

Sizes that fit

The Fanmoss and LainKeen kits fit 3/16, 1/4, 5/16 and 3/8 in tubing, which covers most common sizes for brake, fuel and cooling line repair. The Ailbiuko flaring tool fits the same sizes, while the Ailbiuko and NOLTHKAEL kits include 3/16 and 1/4 in tubing. The Capri kit fits 3/16 in tubing only, so it suits one size and nothing else.

Vise or on the car

Most of these kits need a vise. The Ailbiuko listing says the tool must be used with a vise, so you can only use it on the bench, and the Fanmoss kit works with a bench-mounted vise in the workshop or a hitch-mounted vise in the field, not for under-car use. The LainKeen kit mounts in a vise with a T-handle screw clamp. The Capri tool is the exception: it works both off vehicle and on vehicle, even in tight spots, and its detachable die also works with a bench vise.

What comes in the box

Kits and tool-only boxes are different buys. The Ailbiuko kit includes a flaring tool, a bender, a cutter, 2 x 25 ft of tubing and 100 fittings, and the NOLTHKAEL kit includes a flaring tool, 2 x 25 ft of tubing, 58 fittings, a bender and a cutter. The Fanmoss and LainKeen kits are tool kits with no tubing or fittings listed. The Capri kit sits in between, with a mini tube cutter, a tube bender and 10 mm and 17 mm combination wrenches.

Garage Fit Check

• The Ailbiuko tool must be used with a vise, so plan bench space before you start.
• The Fanmoss kit is not for under-car use, per the listing, so flare the line on the bench.
• Deburr tubing inside and out before flaring, per the Fanmoss listing, and add oil to the flaring cones.
• The Capri tray measures 9.5 in. L. x 7.5 in. W x 2 in. H, so check it fits your tool chest.
• Match the fittings to your line: the Ailbiuko kit includes 3/8-24, 7/16-24, 1/2-20 and 9/16-18 threads.

FAQ: garage tools

What is a brake line flaring tool?

A brake line flaring tool widens the end of a brake line tube into a flare that seals against a fitting, per the LainKeen listing. The kits here make 45 degree single, double and bubble flares, and the LainKeen kit also makes 37 degree flares.

What is flaring a brake line?

Flaring widens the tube end so it seats against the fitting for a leak-free connection, per the LainKeen listing. A single flare uses OP.0 then OP.2, a bubble flare uses OP.0 then OP.1, and a double flare uses OP.0, then OP.1, then OP.2, per the Ailbiuko listing.

Can I flare stainless steel brake lines with these kits?

The LainKeen, Fanmoss and Ailbiuko listings state stainless steel, with the Ailbiuko and Fanmoss listings naming 304 stainless steel. The NOLTHKAEL listing names copper, aluminum and nickel-copper tubing, and the Capri listing states non-stainless steel, so those two do not state stainless use.

Do I need a vise to use a brake line flaring tool?

The Ailbiuko listing says the tool must be used with a vise, and the Fanmoss and LainKeen kits use a vise mount design. The Capri tool works both off vehicle and on vehicle, and its detachable die also works with a bench vise.

What sizes do these flaring tool kits fit?

The Fanmoss and LainKeen kits fit 3/16, 1/4, 5/16 and 3/8 in tubing. The Ailbiuko tool fits the same sizes, while the Ailbiuko and NOLTHKAEL kits include 3/16 and 1/4 in tubing. The Capri kit fits 3/16 in tubing only.

Related: the best double flare brake line tools, the best brake line flaring tools for tight spaces, the best hydraulic brake line flaring tools and our engine and shop equipment hub. Also see how to repair a brake line, the best brake pipe benders, the best tools for changing brakes and the best brake line flaring kits for beginners.