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Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516
Black Oxide Coated Steel Brake Line Fitting 5/16" Compression Union - 4LifetimeLines LTHPCF516

High Pressure Compression Fitting Union | 5/16" | Bag of 1

$3.99
5.0
Rated 5.0 out of 5 stars
4 Reviews

SKU: LTHPCF516

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5/16" High Pressure Compression Union

When you’re running fuel, hydraulic, or brake circuits that can’t afford even a single drip, this 5/16″ high-pressure compression union delivers factory-grade sealing in minutes—no flaring, soldering, or specialty tools. Machined from nickel-plated brass for corrosion resistance up to 1,000 hours salt-spray, it joins two 5/16-inch hard lines and holds tight at pressures beyond 3,000 psi—well above DOT brake-system specs.

Built for brute pressure, built to last

3-piece compression design—ferrules cold-form around steel, copper, or copper-nickel tubing for a gas-tight seal.

Black-oxide plated body—resists road salt, ethanol blends, and most hydraulic fluids.

True high-pressure rating—lab-tested to 3,000 psi+; safe for power-steering, diesel, and brake systems.

Quick install—just square-cut the tube, deburr, slide on nut/ferrule, and tighten to spec.

DOT & SAE compliant—meets FMVSS 106 burst and brake impulse standards when installed on annealed tubing.

Where it works

Fuel hard lines • Hydro-boost brake setups • Power-steering return & pressure lines • Off-road air-locker plumbing • Industrial hydraulic equipment up to 3 kpsi.

How to install (2 min.)

  1. Cut both tube ends square and deburr inside/outside.

  2. Slide compression nut and ferrule onto the tube.

  3. Insert tube fully into union body; finger-tighten nut.

  4. Wrench an additional 1 ¼ turns—or follow torque chart printed on the bag.

  5. Pressure-test to verify leak-free seal.

Pro tip: Use a drop of light oil on the compression threads to achieve full clamp load with less torque.

Here to help

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Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

Lifetime Quality, Covered — for Life

Zero Risk, Maximum Confidence

Built to Endure. Guaranteed to Perform.

One-Time Purchase. Lifetime Assurance.

FREE SHIPPING

Spend $50. We Cover the Rest.

BUILT TO ENDURE

No Weak Points. No Compromises.

LIFETIME WARRANTY

One Purchase. Lifetime Coverage.

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100+ 5 star reviews

“.. easy to get the part you need, when you need it.”

Jackson

Great Experience

Great received day early good product this is 3rd time doing business with 4LifetimeLines

Happy Customer

Great product!! I’ve ordered these before and they are great quality! I’ll be back again.

Excellent

Excellent product shipped quickly and inexpensively. I will be ordering again.

Ideal Products

Ideal stuff for fabricating brake lines brake lines at a very good price.Kit very well covers the materials for doing the whole brake line system.

Reasonable price and fast shipping!

I'll be back again!

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Great seller to deal with. Fast shipping and great products.

Great products, competitive prices, and fast shipping. Communication is also top notch.

This was my first purchase and the experience has been fantastic. Great products, competitive prices, and fast shipping. Communication is also top notch.

Great products, competitive prices, and fast shipping.

This was my first purchase and the experience has been fantastic. Great products, competitive prices, and fast shipping. Communication is also top notch.
5.0
Rated 5.0 out of 5 stars
Based on 4 reviews
Total 5 star reviews: 4 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
100%would recommend this product
4 reviews
  • Rated 5 out of 5 stars
    1 year ago
    I used 5/16 fittings to

    I used 5/16 fittings to splice my transmission cooler lines. These are suitable for high pressure, unlike brass compression fittings on steel lines.

    CG
    Craig G.
  • Rated 5 out of 5 stars
    2 years ago
    Great product

    They work well

    GG
    George G.
  • Rated 5 out of 5 stars
    3 years ago
    Great product

    Used for fuel line repair, worked/looks great.

    PB
    Patrick B.
  • Rated 5 out of 5 stars
    4 years ago
    Quality

    Very nice piece. Worked Perfect for transmission line.

    A
    Allen