Tube Fittings
Double Ferrules Female Connector
Stark female connector for secure tube-to-male-thread integration. Forged 316SS, Swagelok & Parker compatible. Reduces leak points. Ideal for pressure gauges and instrument panels. Request a 24h quote!
Double Ferrules Female Connector Fitting: Reliable Instrumentation Connectivity
Achieve a more robust, compact, and leak-resistant connection for your male-threaded instruments. The Stark Female Connector (SS-FC) is precision-engineered to integrate devices like pressure gauges, transmitters, and male pipe ends directly into a tube line. By eliminating the need for additional adapters, our one-piece forged 316L stainless steel design reduces potential leak paths and simplifies your system layout.
✓ Instrument-Grade Precision| ✓ Reduces System Leak Points| ✓ Zero-Leak Performance Guarantee
🔧 Find Your Connector Size in 3 Clicks
1. Select Tube O.D.:○ 1/4" ○ 1/2" ○ 6mm ○ 12mm ...
2. Select Female Thread Type:○ NPT ○ BSPP ○ SAE/UNF ...
🔥 Most Popular Sizes (In Stock - Same Day Shipping)
1/4" Tube x 1/4" NPT | 1/2" Tube x 1/2" NPT | 6mm Tube x 1/4" NPT | 12mm Tube x 1/2" NPT |
SS-FC-FT4-FN4 | SS-FC-FT8-FN8 | SS-FC-MT6-FN4 | SS-FC-MT12-FN8 |
Part Number Format: [Material]-FC-[Tube Size]-[Thread Size] (e.g., INC625-FC-FT4-FN4)
(FC = Female Connector)
(FT / MT = Sizing System (Fractional Tube / Metric Tube))
🛠 The Engineering Advantage
- System Simplification with One-Piece Design: By providing a direct tube-to-female-thread connection, our connector eliminates a separate male connector and a coupling, reducing two potential leak paths to zero and saving critical installation space.
- Forged Body Integrity for Instrument Mounting: Our female connectors feature a heavy-wall forged body to safely handle the stresses associated with mounting heavy instruments or gauges, ensuring long-term stability.
- Guaranteed Interchangeability: Designed for full dimensional and functional compatibility with Swagelok® and Parker A-LOK® components, facilitating easy upgrades and maintenance without compromising system integrity.
- Reliable Reassembly with Anti-Galling Nuts: Every tube-side nut is internally silver-plated as a standard feature. This prevents thread seizing (galling) and ensures the tube connection can be reliably disassembled and reassembled 20+ timesfor maintenance.
📈 Technical Specifications
Feature | Stark Standard Specification | Optional Advanced Upgrades |
Body Material | Forged316/316L Stainless Steel | Duplex 2205, Super Duplex 2507, Inconel 625, Hastelloy C276, Monel 400, etc. |
Thread Types | NPT, BSPP (ISO 228/1), BSPT (ISO 7/1), SAE/UNF | Custom thread configurations |
Pressure Rating | Up to 10,000 PSI (689 bar) | Custom High-Pressure Configurations |
Testing | 100% Pneumatic Tested at 1.1x WP | Helium Leak Testing (1 x 10⁻⁹ sccs) |
Compliance | MTR to EN 10204 3.1 & PMI Verified | NACE MR0175 / NORSOK M-650 |
🎯 Why Use a Female Connector? A Head-to-Head Comparison
Feature | Using a Coupling + Male Connector | Using One Stark Female Connector |
Potential Leak Paths | ⚠️ 3 (2 thread, 1 tube) | ✅ 2 (1 thread, 1 tube) - 33% Reduction in Leak Risk |
Installation Time | ❌ High (Requires 2 components) | ✅ Low (Single component installation) |
Space Requirement | ❌ Larger, longer footprint | ✅ Compact, Integrated Design |
Total Installed Cost | ⚠️ Higher (2 components + extra labor) | ✅ Lower Total Installed Cost |
📌 Targeted Application Support
- Pressure Gauge Mounting: The most reliable and compact way to connect gauges with male NPT stems to tubing.
- Instrument Panels: Ideal for bulkhead transitions where female threads are required for external connections.
- Sample Systems: Connecting sample cylinders or fast loops to analysis equipment.
- System Drain & Vent Points: Used with a male-threaded plug or bleed valve to create a secure drain or vent point.
❓ Frequently Asked Questions (FAQ)
Q1: What is the main advantage of using a female connector?
The main advantage is system simplification and reliability. By replacing two separate components (a male connector and a coupling) with one, you reduce the number of potential leak paths by 33%, save installation time, and create a more compact and robust connection.
Q2: Which thread type should I choose: NPT or BSPP?
NPT is a tapered thread that seals on the threads. BSPP (G thread) is a parallel thread that seals with a gasket or O-ring. Choose the thread type that matches the male-threaded device you are connecting. They are not interchangeable.
Q3: Are your female connectors suitable for panel mounting?
Standard Female Connectors (SS-FC) are designed for in-line tube-to-thread connections. For applications requiring integration through an instrument panel or enclosure wall, we offer a specialized Bulkhead Female Connector (SS-BFC) version. The SS-BFC series features an extended body and a dedicated panel nut to provide a stable, vibration-resistant mount for your instrumentation layout.
Q4: How do you ensure the female threads are high quality?
Every thread is precision-machined on our CNC equipment and then 100% verified using calibrated thread gauges. This ensures a perfect fit and a reliable seal, preventing common issues like cross-threading and leakage.
📦 Complete Size & Cross-Reference Chart
Fractional Tube x Female NPT
Tube O.D. (in.) | NPT Size (Female) | Stark Part No. | Swagelok® Ref | Parker A-LOK® Ref |
|---|---|---|---|---|
1/16 | 1/16 | SS-FC-FT1-FN1 | SS-100-7-1 | 1FSC1N |
1/16 | 1/8 | SS-FC-FT1-FN2 | SS-100-7-2 | 1FSC2N |
1/16 | 1/4 | SS-FC-FT1-FN4 | SS-100-7-4 | 1FSC4N |
1/8 | 1/8 | SS-FC-FT2-FN2 | SS-200-7-2 | 2FSC2N |
1/8 | 1/4 | SS-FC-FT2-FN4 | SS-200-7-4 | 2FSC4N |
3/16 | 1/8 | SS-FC-FT3-FN2 | SS-300-7-2 | 3FSC2N |
1/4 | 1/8 | SS-FC-FT4-FN2 | SS-400-7-2 | 4FSC2N |
1/4 | 1/4 | SS-FC-FT4-FN4 | SS-400-7-4 | 4FSC4N |
1/4 | 3/8 | SS-FC-FT4-FN6 | SS-400-7-6 | 4FSC6N |
1/4 | 1/2 | SS-FC-FT4-FN8 | SS-400-7-8 | 4FSC8N |
5/16 | 1/8 | SS-FC-FT5-FN2 | SS-500-7-2 | 5FSC2N |
5/16 | 1/4 | SS-FC-FT5-FN4 | SS-500-7-4 | 5FSC4N |
3/8 | 1/8 | SS-FC-FT6-FN2 | SS-600-7-2 | 6FSC2N |
3/8 | 1/4 | SS-FC-FT6-FN4 | SS-600-7-4 | 6FSC4N |
3/8 | 3/8 | SS-FC-FT6-FN6 | SS-600-7-6 | 6FSC6N |
3/8 | 1/2 | SS-FC-FT6-FN8 | SS-600-7-8 | 6FSC8N |
3/8 | 3/4 | SS-FC-FT6-FN12 | SS-600-7-12 | 6FSC12N |
1/2 | 1/4 | SS-FC-FT8-FN4 | SS-810-7-4 | 8FSC4N |
1/2 | 3/8 | SS-FC-FT8-FN6 | SS-810-7-6 | 8FSC6N |
1/2 | 1/2 | SS-FC-FT8-FN8 | SS-810-7-8 | 8FSC8N |
1/2 | 3/4 | SS-FC-FT8-FN12 | SS-810-7-12 | 8FSC12N |
5/8 | 3/8 | SS-FC-FT10-FN6 | SS-1010-7-6 | 10FSC6N |
5/8 | 1/2 | SS-FC-FT10-FN8 | SS-1010-7-8 | 10FSC8N |
5/8 | 3/4 | SS-FC-FT10-FN12 | SS-1010-7-12 | 10FSC12N |
3/4 | 1/2 | SS-FC-FT12-FN8 | SS-1210-7-8 | 12FSC8N |
3/4 | 3/4 | SS-FC-FT12-FN12 | SS-1210-7-12 | 12FSC12N |
7/8 | 3/4 | SS-FC-FT14-FN12 | SS-1410-7-12 | 14FSC12N |
1 | 3/4 | SS-FC-FT16-FN12 | SS-1610-7-12 | 16FSC12N |
1 | 1 | SS-FC-FT16-FN16 | SS-1610-7-16 | 16FSC16N |
1 1/4 | 1 1/4 | SS-FC-FT20-FN20 | SS-2000-7-20 | 20FSC20N |
1 1/2 | 1 1/2 | SS-FC-FT24-FN24 | SS-2400-7-24 | 24FSC24N |
Metric Tube x Female NPT
Tube O.D. (mm) | NPT Size (Female) | Stark Part No. | Swagelok® Ref | Parker A-LOK® Ref |
|---|---|---|---|---|
3 | 1/8 | SS-FC-MT3-FN2 | SS-3M0-7-2 | M3FSC1/8N |
3 | 1/4 | SS-FC-MT3-FN4 | SS-3M0-7-4 | M3FSC1/4N |
4 | 1/8 | SS-FC-MT4-FN2 | SS-4M0-7-2 | M4FSC1/8N |
6 | 1/8 | SS-FC-MT6-FN2 | SS-6M0-7-2 | M6FSC1/8N |
6 | 1/4 | SS-FC-MT6-FN4 | SS-6M0-7-4 | M6FSC1/4N |
6 | 3/8 | SS-FC-MT6-FN6 | SS-6M0-7-6 | M6FSC3/8N |
6 | 1/2 | SS-FC-MT6-FN8 | SS-6M0-7-8 | M6FSC1/2N |
8 | 1/8 | SS-FC-MT8-FN2 | SS-8M0-7-2 | M8FSC1/8N |
8 | 1/4 | SS-FC-MT8-FN4 | SS-8M0-7-4 | M8FSC1/4N |
8 | 3/8 | SS-FC-MT8-FN6 | SS-8M0-7-6 | M8FSC3/8N |
8 | 1/2 | SS-FC-MT8-FN8 | SS-8M0-7-8 | M8FSC1/2N |
10 | 1/8 | SS-FC-MT10-FN2 | SS-10M0-7-2 | M10FSC1/8N |
10 | 1/4 | SS-FC-MT10-FN4 | SS-10M0-7-4 | M10FSC1/4N |
10 | 3/8 | SS-FC-MT10-FN6 | SS-10M0-7-6 | M10FSC3/8N |
10 | 1/2 | SS-FC-MT10-FN8 | SS-10M0-7-8 | M10FSC1/2N |
12 | 1/4 | SS-FC-MT12-FN4 | SS-12M0-7-4 | M12FSC1/4N |
12 | 3/8 | SS-FC-MT12-FN6 | SS-12M0-7-6 | M12FSC3/8N |
12 | 1/2 | SS-FC-MT12-FN8 | SS-12M0-7-8 | M12FSC1/2N |
12 | 3/4 | SS-FC-MT12-FN12 | SS-12M0-7-12 | M12FSC3/4N |
14 | 3/4 | SS-FC-MT14-FN12 | SS-14M0-7-12 | M14FSC3/4N |
15 | 1/2 | SS-FC-MT15-FN8 | SS-15M0-7-8 | M15FSC1/2N |
16 | 3/8 | SS-FC-MT16-FN6 | SS-16M0-7-6 | M16FSC3/8N |
16 | 1/2 | SS-FC-MT16-FN8 | SS-16M0-7-8 | M16FSC1/2N |
20 | 1/2 | SS-FC-MT20-FN8 | SS-20M0-7-8 | M20FSC1/2N |
20 | 3/4 | SS-FC-MT20-FN12 | SS-20M0-7-12 | M20FSC3/4N |
22 | 3/4 | SS-FC-MT22-FN12 | SS-22M0-7-12 | M22FSC3/4N |
22 | 1 | SS-FC-MT22-FN16 | SS-22M0-7-16 | M22FSC1N |
25 | 3/4 | SS-FC-MT25-FN12 | SS-25M0-7-12 | M25FSC3/4N |
25 | 1 | SS-FC-MT25-FN16 | SS-25M0-7-16 | M25FSC1N |
💬 Still Have Questions?
Our engineering team is ready to assist with technical selection, system design, or material recommendations.
🔒 Disclaimer
Swagelok® and Parker A-LOK® are registered trademarks of their respective holders. Stark is not affiliated with, endorsed by, or sponsored by these companies. Part numbers and brand names are provided for cross-reference and compatibility purposes only.