Push-In Fittings

The Right Material for the Job

Demystifying Push-In Fittings: Choosing the Right Material for the Job - Click Here for Our Selection of Push-In Fittings

At BearingBoys, we often get asked: “Which material should I choose for a push-in fitting?” It’s a good question — the material you pick can make a big difference in performance, longevity, and cost. In this post I want to walk you through the main material options for push-in (or push-to-connect) fittings, their advantages and trade-offs, and how they map to different applications.

What Are Push-In Fittings?

Before diving into materials, a quick refresher: push-in fittings (also called push-to-connect, or instant fittings) allow tubing to be inserted into the fitting and held in place by an internal gripping ring, with a sealing O-ring or similar element sealing the interface. The beauty is speed and reusability — you generally don’t need tools, soldering, or adhesive to make or break the connection. 

In our range at BearingBoys, we stock over 780 variants of push-in fittings, covering various shapes (straight connectors, elbows, tees, blanking plugs, etc.) and multiple material types. 

Material Options for Push-In Fittings

Here are the primary material families you’ll commonly see — along with their strengths, limitations, and typical use cases.

1. Plastic / Polymer Push-In Fittings

These are often the first material people think of when they hear “push-in fitting.” Many pneumatic and low-cost systems use plastic bodies (commonly PBT or reinforced PBT in industrial fittings) with internal grip rings (often stainless) and O-rings for sealing.

Pros:

• Lightweight and non-conductive: Good when weight matters or avoiding electrical conduction is desirable.

• Corrosion resistance: Plastics resist many chemicals and moisture better than many metals in many environments.

• Cost efficient: Typically lower manufacturing cost, especially for large runs.

• Ease of configuration: Molding allows complex geometries, built-in features, integrated thread interfaces etc.

Cons / trade-offs:

• Pressure & temperature limits: Plastic fittings often can’t handle the same extremes as metals.

• Material compatibility: Some aggressive chemicals or solvents may degrade certain plastics.

• Creep / fatigue over time: Plastic may deform under constant stress or thermal cycling.

• UV or aging issues: In some cases exposure to sunlight or environmental stressors can degrade polymers.

When to choose plastic:

• In compressed air or pneumatic systems of moderate pressure.

• Where cost or weight is a priority and environmental conditions are benign.

• When corrosion (e.g. from humidity or mild chemicals) is a concern.

At BearingBoys, our plastic push-in fittings come in a variety of forms: straight connectors, tees, blanking plugs, unequal connectors, etc.

2. Brass (Often Nickel-Plated) Push-In Fittings

Brass is a traditional choice for many fluid and pneumatic fittings, often plated (e.g. nickel) to improve corrosion resistance and surface finish.

Strengths:

• Better mechanical strength: Can tolerate more mechanical stress, vibration, pressure compared to many plastics.

• Better temperature tolerance: Brass can survive higher temperatures without softening or deforming.

• Sealing reliability: Due to its stability, it supports consistent sealing performance over time.

• Machining and threading capability: Easier to machine fine tolerances, threads, and interfaces.

Considerations:

• Cost & weight: More expensive and heavier than plastics.

• Corrosion in aggressive media: In some chemical or saline environments, brass may corrode unless properly plated or alloyed.

• Electrically conductive: In some applications that may matter (grounding, insulation).

Typical uses:

• Pneumatic systems under moderate to high pressure.

• Fluid delivery where a more robust material is needed.

• Systems where metal bodies are expected or required by spec or standard.

3. Stainless Steel Push-In Fittings

If you’re working in highly corrosive, hygienic, or demanding environments, stainless steel is often the premium choice. Many manufacturers supply push-in fittings fully constructed from stainless (e.g. 316) with compatible seals (e.g. Viton / FKM) for chemically aggressive or washdown conditions.

Advantages:

• Excellent corrosion resistance: Ideal in harsh, marine, chemical or sanitary environments.

• High strength & durability: Very robust under mechanical stress, vibration, and thermal cycling.

• Wide temperature range: Performs well under extreme hot or cold conditions.

• Longevity & cleanliness: Suitable for food, beverage, pharmaceutical, or washdown environments.

Trade-offs / challenges:

• Higher price: Material and machining costs are significant.

• Manufacturing precision required: Tighter tolerances needed to maintain sealing, plus compatibility with sealing materials.

• Weight: Heavier than plastics, though often acceptable in such use cases.

Ideal applications:

• Food & beverage, pharmaceutical, biotech, sanitary systems.

• Marine, offshore, or corrosive chemical delivery.

• Anywhere hygiene, washdown, or longevity is critical.

Many stainless push-in fittings use FKM (Viton) seals for compatibility with a wide range of chemicals and temperatures.

How to Choose the Right Material

When selecting a push-in fitting material, I like to think through a few guiding questions:

1. What pressures and temperatures will the system see? Go for stronger materials (brass, stainless) when extremes or spikes are expected.

2. What’s the chemical or environmental exposure? For aggressive mediums, stainless or compatible plastics are safer.

3. How critical is longevity and maintenance? In hard-to-reach systems, durability matters more.

4. Weight, cost, and manufacturing constraints: If weight or budget is tight, plastic options may win.

5. Standards or certifications: Food, medical, or hygienic systems may demand stainless or approved materials.

For many general-purpose pneumatic applications, a high-quality plastic push-in fitting is more than adequate. But when you step into harsher or more regulated conditions, brass or stainless steel often become the safer bets.

Final Thoughts

At BearingBoys, we believe in helping our customers make informed choices. Our push-in fittings range covers all these material types, shapes and sizes, so you can tailor your selection to your actual environment and application.

If you ever find yourself unsure which material to pick — or want help matching a fitting to your tubing, pressure, or chemical environment — just drop us a message. We’re happy to help you find the best fit (literally!).