Tube fittings Inforamtion

SK Tube fittings are manufactured to stringent quality control program and internal standards which assure the highest quality available. Twin Ferrule Tube Fittings consists of four precisely machined components for a 100% Reliable LEAK PROOF joint. The function of the Back Ferrules is to provide a excellent and Anti vibration hold on the Tube. The function of the Front Ferrule is to provide a Pressure Seal between the Tube and the Body. Silver plating on the Nuts ensures No Galling on Body threads. Tube Fittings are designed to compensate variation in Tubing materials, hardness and wall thickness. Tube Fittings are Gaugeable for sufficient pull-up and allows repeated remake ability. These fittings are available for fractional and metric Tubes with the choice of Pipe threads, i.e NPT, BSP/ BSPT, SAE.

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Tube Fittings has been designed for use in instrumentations, process & control system, analyses and environment employed in chemical, petroleum, power generating, Automobiles, Nuclear, Oil & gas, Ship Building, Power Plants, Process Instrumentation, Aerospace & Defence, CNG Stations.

Tube Fittings are available in assembled and ready to use conditions to provide a reliable and leak-proof connection in instrumentation and process tubing systems. The installation of these Tube Fittings is very simple. Just insert the tube inside the Tube Fittings Assembly and tighten the nut as per assembly (1.1/4 turn from finger-tight) and the joint is ready to take any kind of pressures from low to high. The front ferrule, as it is urged forward against the tapered area of the body is forced inward gripping and subsequently sealing the leading edge tightly onto tubing. Simultaneously the back ferrule, dove tailed directly behind the front ferrule, swages beneath its trailing edge affording the desired "coining" action and mechanical connection of tubing and fitting. It is this interaction of ferrules that allows SK to achieve its excellent sealing capabilities under a wide variety of application variables.

Technical Specifications:

Tube Fitting Fractional Size Are Available: 1/16” to 2”

Tube Fitting Metric Size Are Available: 3mm to 50mm

Design and Standard:

Two ferrule compression tube fittings are manufactured under strict quality control program and close tolerances. There is no international / national standard which is followed by tube fitting manufacturers to manufacture these fittings. Every manufacturer have their own design and tolerances which governs the product specifications. Hence for safety purpose, we do not recommend interchange and intermix the components manufactured by different manufacturers.

Material of Construction:

Tube Fittings are available in MOC 316 stainless steel as a standard. Tube fittings can also be manufactured in Brass, SS 316L, Monel and other exotic alloys upon request. Raw material outsourced meets requirements of one or more following ASTM specifications.

Material Bar Stock Forging
Stainless Steel

ASTM A 276 / A479 SS316

DIN 4401


ASTM A 182 SS316

DIN 4401



ASTM B16 Alloy 360



ASTM B 453 Alloy 345

ASTM B 124 Alloy 377



BS 2872 CZ 122

Alloy 400 (Monel) ASTM B 164 / ASME SB 164 ASTM B 564 / ASME SB 564
Alloy 825 (Inconel) ASTM B 425 ASTM B 564 / ASME SB 564
Alloy C-276 (Hastelloy) ASTM B 574 ASTM B 564
SAF 2507 (Super Duplex) ASTM A 479 ASTM A 182


Thread Specifications:

Specifications/standards given in the following table are followed for threaded end of the tube fittings.

End Connection Thread Type Reference Specifications
NPT ASME B1.20.1, SAE AS71051
ISO/BSP Parallel ISO 228
ISO/BSP Tapered ISO 7, BS EN 10226-1
SAE (Unified) ASME B1.1


Always use thread sealants on pipe threads. Do not apply sealant / PTFE on tube end of fitting.

Always use O-rings / Gaskets with parallel threads.


All the Fitting manufactured by us are ultrasonically cleaned and free from oil and other impurities.