Stainless Steel NPT Hydraulic Fittings & Adapters Manufacturer
Hydraxio manufactures precision stainless steel NPT hydraulic fittings and adapters engineered to ANSI/ASME B1.20.1 standards. Our products are fully interchangeable with leading brands such as Parker, SSP, Brennan, and Aeroquip.
NPT (National Pipe Taper) threads feature a 60° tapered design that ensures tight sealing through thread interference, making them ideal for high-pressure hydraulic and fluid transfer systems. NPTF (Dryseal) threads provide enhanced leak-free performance without the need for additional sealing compounds.
Manufactured from premium AISI 304 and 316 stainless steel, our NPT fittings deliver excellent corrosion resistance, durability, and long-term reliability in demanding industrial environments such as oil & gas, chemical processing, and fluid handling systems.
Quick Details:
• Size Range: 1/8″ – 2″
• Thread Type: NPT / NPTF / NPSM
• Connection Types: NPT × JIC / NPT × BSP / NPT × ORFS
• Material Grades: AISI 304 / 316 / 316L / 316Ti
• Product Types: Straight, 45° & 90° Elbow, Tee, Cross, Reducer, Plug, Cap
• Standards: ANSI/ASME B1.20.1(NPT), ANSI/ASME B1.20.3(NPTF)
Types of Stainless Steel NPT Hydraulic Adapeters
Our stainless steel NPT hydraulic adapters are available in a wide range of configurations to meet different connection requirements in high-pressure fluid systems. Designed with NPT and NPTF threads, these fittings ensure reliable sealing performance and excellent corrosion resistance across various industrial applications.
Male NPT Hydraulic Adapter
(SS-5404 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to connect NPT threaded components with reliable, leak-resistant sealing in high-pressure systems.
Female NPT Coupling
(SS-5000 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to connect two male NPT threads, ensuring secure sealing and stable fluid transfer performance.
Hollow Male NPT Plug
(SS-5406-HHP Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed for pressure control or flow applications with dependable sealing performance.
NPT Male Plug
(SS-5406-P Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to securely seal unused ports and prevent leakage in hydraulic systems.
Female Male NPT Bushing Adapter
(SS-5406 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to reduce thread size between NPT connections with reliable, leak-resistant sealing in high-pressure systems.
Female Male NPT Reducer Adapter
(SS-5405 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed for size transition between different NPT threads with stable sealing performance in fluid systems.
Male NPT 90° Elbow
(SS-5500 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to change flow direction by 90° with secure, leak-resistant performance in hydraulic systems.
Female NPT 90° Elbow
(SS-5504 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to provide directional flow control with reliable sealing in high-pressure applications.
Male Female NPT 45° Elbow
(SS-5503 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to redirect flow at 45° with smooth fluid transition and dependable sealing performance.
Male Female NPT 90° Elbow
(SS-5502 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed for flexible installation in compact spaces with leak-resistant sealing performance.
Male NPT Tee
(SS-5600 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to branch fluid flow with secure, leak-resistant connections in hydraulic systems.
Female Male NPT Street Tee
(SS-5602 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed for compact branching connections with reliable sealing in high-pressure applications.
Female Male NPT Branch Tee
(SS-5604 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to create branch connections in hydraulic systems with reliable, leak-resistant sealing performance.
Female NPT Tee
(SS-5605 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316
Designed to branch fluid flow in hydraulic systems with reliable, leak-resistant sealing performance.
Female NPT Cross
(SS-5652 Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316L
Designed to create branch connections in hydraulic systems with reliable, leak-resistant sealing performance.
Female NPT Cap
(SS-5406-C Series)
Available in sizes 1/8″–2″.
Material: SS 304 / SS 316 / 316
Designed to securely seal the end of NPT threaded connections and prevent leakage in fluid systems.
NPT Thread Size Chart & Dimensions (ANSI/ASME Standard)
NPT (National Pipe Taper) and NPTF (Dryseal) hydraulic fittings use a tapered thread design with a 60° thread angle to achieve sealing through thread interference. NPTF threads provide enhanced leak-free performance without the need for additional sealing compounds. The table below shows standard thread sizes, threads per inch, and corresponding outer diameters for accurate identification and system compatibility.
All stainless steel NPT/NPTF hydraulic fittings are manufactured in accordance with ANSI/ASME B1.20.1/B1.20.3 standards.
| Inch size | Dash size | Threads per Inch | Male Thread O.D. (in) | Female thread O.D (in) | ||
|---|---|---|---|---|---|---|
| 1/8 | -2 | 27 | 13/32 | 0.41 | 3/8 | 0.38 |
| 1/4 | -4 | 18 | 17/32 | 0.54 | 1/2 | 0.49 |
| 3/8 | -6 | 18 | 11/16 | 0.68 | 5/8 | 0.63 |
| 1/2 | -8 | 14 | 27/32 | 0.84 | 25/32 | 0.77 |
| 3/4 | -12 | 14 | 1 1/16 | 1.05 | 1 | 0.98 |
| 1 | -16 | 11 1/2 | 1 5/16 | 1.32 | 1 1/4 | 1.24 |
| 1 1/4 | -20 | 11 1/2 | 1 21/32 | 1.66 | 1 19/32 | 1.58 |
| 1 1/2 | -24 | 11 1/2 | 1 29/32 | 1.90 | 1 13/16 | 1.82 |
| 2 | -32 | 11 1/2 | 2 3/8 | 2.38 | 2 5/16 | 2.30 |
Pressure Rating of NPTF & NPSM Hydraulic Tube Fittings
The pressure rating of NPTF (Dryseal) and NPSM hydraulic fittings depends on thread type, sealing method, material grade, and fitting size. NPTF threads provide sealing through thread interference, while NPSM threads require additional sealing methods such as O-rings or gaskets.
The table below shows typical pressure ratings for different sizes and configurations, ensuring safe operation and reliable performance in hydraulic and fluid transfer systems.
| SAE Dash Size | Inch Tube O.D | Thread Size | Working Pressure of NPTF Male/Female(Mpa) | Working Pressure of NPSM Female Swivel(Mpa) |
|---|---|---|---|---|
| -2 | 1/8" | 1/8-27 | 34.50 | 34.50 |
| -4 | 1/4" | 1/4-18 | 27.50 | 27.50 |
| -6 | 3/8" | 3/8-18 | 21.00 | 21.00 |
| -8 | 1/2" | 1/2-14 | 21.00 | 21.00 |
| -12 | 3/4" | 3/4-14 | 17.00 | 17.00 |
| -16 | 1" | 1-11 1/2 | 14.00 | 14.00 |
| -20 | 1 1/4" | 1 1/4-11 1/2 | 8.00 | 8.00 |
| -24 | 1 1/2" | 1 1/2-11 1/2 | 7.00 | 7.00 |
| -32 | 2" | 2 -11 1/2 | 7.00 | 7.00 |
Pressure Rating Notes
• Pressure ratings shown are for stainless steel adapters under normal operating conditions.
• Working pressure decreases as dash size increases.
• Always consider system temperature, vibration, and assembly torque during installation.
Stainless Steel NPT Adapters Cross Reference to Parker & Other Brands
Hydraxio’s SS hydraulic adapter fittings are completely equivalent to Parker, TITAN, Aeroquip, Brennan & Tompkins. Here are the quick details:
| Hydraxio | SAE | Parker | Aeroquip | TITAN/BI/Tompkins |
|---|---|---|---|---|
| SS-5404 Series | 140137 | FF-SS Series | 259-2083 Series | SS-5404 Series |
| SS-5000 Series | 140138 | GG-SS Series | 259-2096 Series | SS-5000 Series |
| SS-5406-HHP Series | 140109N | HHP-SS Series | 259-2222 Series | SS-5406-HP Series |
| SS-5406-P Series | 140109E | HP-SS Series | 259-2082 Series | SS-5406-P Series |
| SS-5406 Series | 140140 | PTR-SS Series | 259-2081 Series | SS-5406 Series |
| SS-5405 Series | 140139 | FG-SS Series | 259-2040 Series | SS-5405 Series |
| SS-5500 Series | 140237 | CR-SS Series | 259-2085 Series | SS-5500 Series |
| SS-5504 Series | 140238 | DD-SS Series | 259-2087 Series | SS-5504 Series |
| SS-5503 Series | 140339 | CD45-SS Series | 259-2088 Series | SS-5503 Series |
| SS-5502 Series | 140239 | CD-SS Series | 259-2089 Series | SS-5502 Series |
| SS-5600 Series | 140437 | RRS-SS Series | 259-2257 Series | SS-5600 Series |
| SS-5602 Series | 140424 | MRO-SS Series | 259-2092 Series | SS-5602 Series |
| SS-5604 Series | 140425 | MMS-SS Series | 259-2091 Series | SS-5604 Series |
| SS-5652 Series | 140538 | KMMO-SS Series | 259-2080 Series | SS-5652 Series |
| SS-5406-C Series | HPC-SS Series | SS-5406C Series |
Applications of Stainless Steel NPT Hydraulic Fittings
Stainless steel NPT hydraulic fittings are widely used in high-pressure hydraulic and fluid transfer systems where reliable sealing and corrosion resistance are essential.
With tapered thread sealing (NPT/NPTF) and durable stainless steel construction, these fittings provide leak-resistant performance in demanding industrial environments.
Construction & Heavy Machinery
Vibration-resistant connections in mobile hydraulic systems.
Oil & Gas Equipment
High-pressure hydraulic lines exposed to aggressive environments.
Marine & Shipbuilding
Saltwater-resistant hydraulic systems requiring corrosion protection.
Agricultural Equipment
Outdoor hydraulic applications exposed to moisture and environmental stress.
Industrial Hydraulic Systems
Long-term durability in factory hydraulic operations.
Chemical Processing Industry
Stainless steel performance in corrosive fluid systems.
Frequently Asked Questions
NPT threads require sealing compounds such as PTFE tape, while NPTF (Dryseal) threads are designed to provide a leak-resistant seal through thread interference without additional sealing materials.
Yes, stainless steel NPT fittings are widely used in high-pressure hydraulic and fluid systems. Their tapered thread design ensures reliable sealing, especially when properly installed.
Our NPT fittings are manufactured from high-quality stainless steel, including AISI 304, 316, and 316L, providing excellent corrosion resistance and durability.
Yes, our stainless steel NPT hydraulic fittings are manufactured to ANSI/ASME standards and are fully interchangeable with major brands such as Parker, SSP, Brennan, and Aeroquip.
Working pressure depends on dash size, thread configuration, and material grade. Stainless steel JIC adapters are designed for high-pressure hydraulic systems and can handle demanding industrial applications when properly installed.
Yes, we provide OEM services including custom thread configurations, drawing approval, and private labeling to meet specific project requirements.
Why Partner with Hydraxio for Stainless Steel Hydraulic Fittings?
✔ 20+ Years Stainless Steel Specialization
✔ 50+ CNC Precision Machines
✔ ISO-Certified Production & Inspection
✔ Global Bulk Supply to 50+ Countries
✔ OEM & Brand-Compatible Solutions
