NPTLOK, Your Trusted Ferrule Fittings Manufacturer
Single Ferrule & Double Ferrule, one supplier covers both
- Custom ferrule hardening, we do standard edge hardening or full-edge on request.
- Lasers mark both the fitting body AND the ferrule.
- 100% hydraulic and pneumatic pressure tested.
- ASTM A269 & A312 certified.
One Supplier for All Your Ferrule Fitting Needs
As a professional ferrule fitting manufacturer, we don’t force you into one type. We offer both single ferrule and double ferrule options, you pick what fits your system.
Need a specific material: We’ve got you covered. Choose SS304 or SS316 stainless steel for high pressure, corrosive media, or harsh environments. Or choose brass for water, air, and general industrial use where budget matters.
Size: From 1/8″ to 1″ OD. Covers most instrumentation and hydraulic tubing.
Thread standard: NPT, BSP, or metric. Male, female, or male-to-female. Tell us what your system uses.
One supplier. All the options. No compromise.
Why Choose Our Ferrule Fittings
- We own our factory. Faster delivery. Stable quality control
- Over 20 years in ferrule fittings. Our machinists have 6+ years on the lathe
- Mature supply chain around the world, ferrule fittings have been exported to the USA, England, Indonesia, Singapore, Myanmar, Pakistan, etc
- 100% hydraulic and pneumatic pressure tested, test videos available
- Complete set of certificates including ASTM A269 & A312, and material test certificate of ferrule fittings
- MOQ from 10 pcs, allowing you to try before making a larger purchase
Why You Need NPTLOK Ferrule Fittings
MTC available. Heat number marked on every fitting.
A269 and A312 certified. Full paperwork included.
Union, elbow, tee, cross, bulkhead. All types available.
Hydraulic and pneumatic pressure test. Every batch.
Ferrule Fittings vs Other Compression Fittings
| Type | Sealing Principle | Pressure Rating | Typical Applications |
| Ferrule (Single or Double) | Metal ferrule bites into tube OD | High (10k-15k psi) | Instrumentation, hydraulic, high pressure gas |
| Rubber Seal Compression | Rubber or plastic seal compresses | Low | Air, water, low pressure fluid |
| Flare | Tube end flared, nut compresses | Medium | Refrigeration, automotive fuel lines |
Key Difference: Ferrule fittings, like ours, use metal-to-metal sealing. No rubber to dry out or crack. They hold up under high-temperature, and high-pressure environments. If your system runs at high pressure, sees vibration, or handles corrosive media, don’t trust rubber seals. Choose our ferrule fittings. They’re built to last where others fail.
Stainless Steel vs Brass, Which One Do You Need for Ferrule Fittings？
Stainless Steel (SS304/SS316)
- Pressure rating: up to 15,000 psi (depends on size and design)
- Temperature: -200°C to +650°C (with proper packing)
- Best for: Chemical plants, marine, high pressure hydraulics, instrumentation, high temperature, corrosive media
Choose stainless steel when your ferrule fitting runs at high pressure, sees corrosive fluids, or operates in harsh environments. It costs more. But it lasts.
Brass
- Pressure: Up to 3,000 psi
- Temperature: -20°C to +200°C
- Ideal for: Water lines, compressed air systems, and low-pressure hydraulic applications, making it a great choice for general industrial uses, especially when budget is a concern.
Choose brass when your ferrule fitting runs at low pressure, handles air or water, and you need to control costs. It won’t handle corrosive media or high temperatures.
Quick Tips
- High pressure, high heat: Stainless Steel
- Low pressure, air, water, budget matters: Brass
Not sure? Tell us your pressure, temperature, and media. We’ll recommend the right material.
Rear Ferrule Hardening: Standard or Customized to Your Requirement
The rear ferrule has to bite into the tube. So we harden the edge that does the biting. Most of the time, we only harden that one edge. Leave the rest of the ferrule softer. Why? Because if you harden the whole thing, it gets harder to tighten. You need more torque. And most people don’t want that.
Sometimes, a customer asks us to harden every edge. Every single one. Like the picture you sent. That’s fine too.
So which one do you need？
If you don’t know, go with our standard. It works for 95% of people.
If you know exactly what you want and you need full-edge hardening, just tell us. We’ll make it.
Laser Marking: On the Body. And on the Ferrule.
Most suppliers only mark the body. Take the fitting apart, and you’re left with loose ferrules. No way to tell which is which.
We mark both. The body gets the part number. Ferrule gets marked too.
So when your crew opens a panel, they know what they’re holding. No guessing. No digging for paperwork.
Need a specific marking? Just tell us. We’ll put it on both.
Why NPTLOK for Ferrule Fittings？
We make ferrule fittings. Been doing it for over 20 years. Own factory. Own people. No middleman.
What you get：
- Direct price. No markup from a distributor.
- Fast lead time. 15-20 days for standard sizes.
- Low MOQ. 10 pieces per size. Try us first.
- Full paperwork. MTC, test certs. In the box.
- Swagelok compatible. Same fit. Lower price.
One supplier for single ferrule, double ferrule, and replacement sets.
Need something custom？Different hardening? Special marking? Non-standard size? Just ask.
Learn More about Us
- ISO-9001 Certificate
- MTC
- EAC1
- EAC2
- EAC3
- EAC4
- EAC5
The ferrule bites into the tube to seal and grip. If it’s softer, it won’t bite. It’ll just slip.
Not recommended. Once tightened, the ferrule is permanently deformed. Reusing it may cause leaks. Always use a new ferrule.
Double ferrule fittings need bright annealing tubes. Single ferrule fittings work with pickled tubes. Use the wrong tube and the seal will fail.
Not sure what you have? Send us a sample. We’ll help you check.
Single ferrule uses one piece to seal and grip. Double ferrule uses two: front seals, back grips.
Pick a single ferrule for low pressure, no vibration, and tight budget.
Pick a double ferrule for high pressure, pumps, engines: anywhere things shake. It costs more but holds better.
