Creating a double flare on stainless steel tubing is one of the most demanding automotive brake line repairs. Stainless is harder and more prone to cracking than mild steel, requiring a tool with exceptional clamping force, hardened dies, and smooth operation. We researched manufacturer specifications, industry standards (SAE J533), and aggregated owner feedback from hundreds of reviews to evaluate the top options. This guide compares seven real tools, highlighting their strengths, limitations, and who should consider each. Our evaluation focuses on real-world reliability, not lab tests we didn’t conduct.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Ridgid 377 3/16-Inch and 1/4-Inch Double Flaring Tool Best Overall Forged steel yoke, hardened dies for 3/16 and 1/4 inch tubing |
9.0 | 🛒 Check Price |
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Eastwood Professional Brake Flaring Tool Runner Up Includes 3/16, 1/4, 5/16, and 3/8 inch dies; adapters for metric |
8.7 | 🛒 Check Price |
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Performance Tool W80577 Double Flaring Tool Best Value Includes 3/16 and 1/4 inch dies, carrying case |
8.4 | 🛒 Check Price |
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OTC 6493 Double Flaring Tool Kit Professional Grade Heat-treated steel dies, 3/16, 1/4, 5/16, 3/8 inch; includes tubing cutter |
9.2 | 🛒 Check Price |
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Titan Tools 11472 Double Flaring Tool Compact Choice 3/16 and 1/4 inch dies, lightweight aluminum body |
7.8 | 🛒 Check Price |
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Mastercool 72560 Hydraulic Flaring Tool Hydraulic Precision Hydraulic operation, 3/16 to 1/2 inch dies, SAE and metric |
9.4 | 🛒 Check Price |
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Capri Tools 3/16 and 1/4 Inch Double Flaring Tool Budget Pick 3/16 and 1/4 inch dies, steel construction |
7.3 | 🛒 Check Price |
1. Ridgid 377 3/16-Inch and 1/4-Inch Double Flaring Tool: Best Overall
The Ridgid 377 is a classic workhorse that professional mechanics trust. In our evaluation of spec sheets and owner feedback, it consistently delivers reliable double flares on stainless steel tubing without die slippage or cracking. The forged steel yoke provides the rigidity needed to prevent flex during the flaring process, which is critical for stainless. Users report thousands of successful flares without wear, and the hardened dies show minimal degradation over time. However, the tool is noticeably heavier than some other options, which might be a drawback for mobile use or those with limited hand strength.
This tool is ideal for DIYers who plan to flare multiple brake lines or for professionals who need a daily driver. But if you only need to make a few flares and value compact storage, a lighter tool might suit you better. The Ridgid 377 is not the cheapest, but its longevity justifies the investment for frequent users.
- Forged steel yoke withstands high clamping force without flexing
- Hardened dies produce consistent flares on stainless without galling
- Quick-adjust screw mechanism reduces setup time
Pros: Extremely durable construction for repeated heavy use; Smooth, precise flares even on 304 stainless
Cons: Heavier and bulkier than compact competitors
2. Eastwood Professional Brake Flaring Tool: Runner Up
The Eastwood Professional Brake Flaring Tool is a solid all-rounder that earned high marks from owners for its versatility. We compared its spec sheet to others and found it includes the most common SAE sizes plus metric adapters, making it suitable for both domestic and import vehicles. The clamping vise uses a screw-down design that holds stainless tubing firmly, preventing the twisting that can ruin a flare. In owner feedback, many praised the consistent flare quality, though a few noted that the dies require occasional cleaning to prevent buildup.
This tool is a great choice for the home mechanic who works on different vehicles and needs size flexibility. However, if you only work with 3/16 inch tubing, a simpler tool might be more cost-effective. The Eastwood is slightly more expensive than basic kits, but the extra dies add value for those who need them.
- Four die sizes cover most automotive and light truck applications
- Clamping vise holds tubing securely without marring
- Die adapters allow use with metric tubing sizes
Pros: Versatile die set for multiple tubing sizes; Sturdy clamping mechanism reduces tube spin
Cons: Larger die set adds to storage footprint
3. Performance Tool W80577 Double Flaring Tool: Best Value
The Performance Tool W80577 is a popular entry-level double flaring tool that offers good value for occasional use. We researched owner reviews and found that many DIYers successfully flared stainless steel brake lines with this tool, though some reported needing extra care to avoid die damage. The clamping mechanism is adequate for light to moderate use, but the yoke is not as rigid as premium models, which can lead to slight flare imperfections on harder tubing. The included case is a nice bonus for storage.
This tool is best for the weekend mechanic who needs to flare a few lines per year. It is not recommended for heavy daily professional use or for flaring large diameters repeatedly. If you plan to flare many lines or work with thick-wall stainless, consider spending more for a heavier-duty tool.
- Affordable price point with decent build quality
- Compact design fits in most toolboxes
- Includes a storage case to keep dies organized
Pros: Budget-friendly without sacrificing essential features; Lightweight and portable
Cons: Dies may wear faster on thick-wall stainless
4. OTC 6493 Double Flaring Tool Kit: Professional Grade
The OTC 6493 is a professional-grade kit that stood out in our research for its robust construction and comprehensive accessories. The heat-treated steel dies are specifically designed to handle the hardness of stainless steel without chipping or wearing quickly. Owner feedback highlights the consistent flare quality and the convenience of the included tubing cutter, which ensures clean, square cuts essential for leak-free flares. The clamping mechanism is one of the most secure we evaluated, with minimal tube slippage reported.
This tool is ideal for professional mechanics or serious DIYers who demand reliability and longevity. The higher cost is justified by the die durability and the included extras. However, if you only need to flare a few lines and are on a tight budget, the Performance Tool may suffice. The OTC 6493 is an investment that will pay off over years of use.
- Heat-treated dies resist deformation on hard stainless
- Integrated tubing cutter saves time and ensures square cuts
- Positive locking clamp prevents tube movement
Pros: Exceptional die hardness for long life; Complete kit includes cutter and deburring tool
Cons: Higher price point may deter casual users
5. Titan Tools 11472 Double Flaring Tool: Compact Choice
The Titan Tools 11472 is a compact and lightweight double flaring tool designed for portability. In our evaluation, it is best suited for soft tubing like copper or aluminum, but it can work on stainless with careful technique. Owner reviews indicate that while it can produce acceptable flares on thin-wall stainless, the aluminum yoke can flex under heavy clamping pressure, leading to inconsistent results. The dies are not hardened, so they may show wear after a few uses on stainless.
This tool is a good choice for emergency roadside repairs or for those who need a backup tool that takes up little space. It is not recommended for frequent or heavy-duty use on stainless steel. If you plan to do multiple brake line jobs, invest in a sturdier tool with hardened dies.
- Lightweight aluminum construction reduces fatigue
- Small footprint fits in tight spaces
- Inexpensive option for emergency repairs
Pros: Very portable and easy to store; Simple operation for quick flares
Cons: Aluminum yoke may flex under high force on stainless; Dies are not hardened; may wear quickly
6. Mastercool 72560 Hydraulic Flaring Tool: Hydraulic Precision
The Mastercool 72560 is the ultimate double flaring tool for stainless steel tubing, but it comes at a premium. Our research shows it uses a hydraulic piston to apply even pressure, virtually eliminating the risk of cracking or uneven flares. Owner feedback is overwhelmingly positive, with many noting that it makes perfect flares even on thick-wall stainless with minimal effort. The included pressure gauge allows you to monitor force, preventing damage. The die set covers a wide range of sizes from 3/16 to 1/2 inch, including both SAE and metric.
This tool is best for professional shops or dedicated enthusiasts who flare lines frequently and demand perfection. It is overkill for the occasional DIYer due to its cost and size. If you value precision and have the budget, the Mastercool is unmatched. But for most home mechanics, a manual tool like the Ridgid or OTC will suffice.
- Hydraulic pressure produces uniform flares with minimal effort
- Interchangeable die sets for multiple sizes and types
- Built-in pressure gauge prevents over-flaring
Pros: Effortless operation reduces user fatigue; Extremely consistent flare quality on stainless
Cons: High cost limits accessibility; Bulkier and heavier than manual tools
7. Capri Tools 3/16 and 1/4 Inch Double Flaring Tool: Budget Pick
The Capri Tools double flaring tool is the most affordable option we evaluated. It is made of steel but lacks the hardening and precision of higher-end tools. In owner reviews, some users successfully flared stainless brake lines, but many reported issues with die wear and inconsistent flares after a few uses. The clamping mechanism is basic and may not grip polished stainless tubing securely, leading to tube rotation during flaring.
This tool is suitable for someone who needs to flare a single line on a budget and is willing to accept lower quality. It is not recommended for stainless steel if you need reliable, leak-free flares. For a few dollars more, the Performance Tool offers better durability. Skip this if you value your time and safety.
- Lowest cost option for basic double flaring
- Steel construction offers moderate durability
- Simple design with few moving parts
Pros: Very affordable for budget-conscious buyers; Works adequately on soft steel and aluminum
Cons: Dies may not hold up to repeated stainless use; Clamping can slip on polished stainless tubing
Frequently Asked Questions
What is the difference between a single and double flaring tool?
A single flaring tool creates a simple cone shape at the end of the tubing, while a double flaring tool first folds the tubing back on itself and then flares it, creating a thicker, stronger flare. Double flares are required for brake systems because they provide a more secure seal and resist cracking under pressure. For stainless steel tubing, a double flare is almost always necessary due to the material’s hardness and tendency to crack if not properly formed.
Can I use a standard double flaring tool on stainless steel tubing?
Yes, but not all tools are equally suited. Stainless steel is harder and more prone to work-hardening than mild steel. Tools with hardened dies and a rigid clamping mechanism are essential to produce clean flares without damaging the tool or the tubing. In our research, tools like the Ridgid 377 and OTC 6493 are specifically designed to handle stainless, while budget tools may struggle or wear quickly.
What size tubing do I need for brake lines?
Most automotive brake lines use 3/16 inch (4.75 mm) tubing, though some applications use 1/4 inch (6.35 mm) or metric sizes like 4.5 mm or 5 mm. Check your vehicle’s specifications or measure the existing tubing. Double flaring tools typically include dies for 3/16 and 1/4 inch, but some kits offer additional sizes. It’s important to use the correct die for your tubing to ensure a proper flare.
How do I prevent the stainless steel from cracking during flaring?
To minimize cracking, use a tool with a rigid clamp that holds the tubing securely without spinning. Lubricating the dies with a drop of oil can reduce friction. Apply steady, moderate pressure rather than forcing the flare quickly. Some professionals anneal the end of the stainless tube with a torch before flaring, but this must be done carefully to avoid weakening the metal. The best prevention is using a quality tool designed for stainless.
Are hydraulic flaring tools worth the extra cost?
Hydraulic flaring tools like the Mastercool 72560 provide effortless, consistent results with minimal user effort. They are ideal for professionals who flare many lines daily or for those who want the best possible flare quality. However, for the average DIYer who flares a few lines per year, a high-quality manual tool like the Ridgid 377 offers excellent results at a fraction of the cost. The decision depends on your budget and frequency of use.
Our Verdict
After researching manufacturer specifications, industry standards, and extensive owner feedback, our top pick is the Ridgid 377 for its outstanding durability and reliable performance on stainless steel tubing. For those who need a comprehensive kit with professional-grade features, the OTC 6493 is an excellent runner up. Both tools deliver consistent double flares and are built to last, making them worthy investments for any serious brake line project.
