Circular connectors

Comprehensive Connectivity Solutions

Fischer circular connectors cater to a wide range of applications, including low/high voltage, coaxial and triaxial connections, hybrid designs, fiber optics, push-pull mechanisms, and even fluid or gas transmission. With over 30,000 circular connector product references, Fischer ensures reliable power, signal, and data connectivity.

Engineered for Performance

Backed by more than 70 years of expertise, Fischer connector solutions excel in harsh environments, offering superior durability, sealing, hermeticity, miniaturization, high-density configurations, and flawless data transmission.

Customizable Options

Choose from an extensive selection of shell sizes, keying configurations, and pin layouts to meet your specific requirements.

Circular Connectors by Application

Waterproof connectors — Waterproof Connectors

Hermetic connectors — Hermetic Connectors

Miniature connectors — Miniature Connectors

High speed connectors — High-Speed Connectors

Military connectors — Military Connectors

All Our Series Feature Rugged Connectors

Heavy-use or safety-critical applications are designed to withstand mechanical stress and environmental conditions without compromising power, signal, or data transmission.

Built to Endure Toughest Conditions

Our circular connectors, cables, and electronic solutions are built with robust materials and a rugged design:

Mechanical Endurance: Resists abrasion, wear, and intensive use – up to 10,000 mating cycles without any loss of signal.

Design and Assembly Robustness: Resistance to vibration and shock, safe and robust locking mechanisms.

Error-proof blind mating, color-coded identification, and cable tensile strength up to 400 N.

360° Shielding: EMI/RFI protection for secure and faultless data transmission.

Ruggedization Methods and Processes

Our ruggedization methods pertain to the entire designing, engineering, and manufacturing chain of our circular connectors, cable assemblies, and electronic solutions. This includes choosing high-quality materials for housing, coating, plating, insulating, and sealing, as well as overmolding or jacketing cables to protect the insulation and conductor core against environmental aggression and chemical deterioration.

Resistance of Our Materials

Check out which material is most suitable for your application.

Material Resistance Table

Shell Material

Material Name	Ideal For	Temperature	Main Attributes
Chromium-plated brass	Ruggedness	-100 to +200°C	Salt mist and mechanical resistance, cost efficiency, electrical conductivity
Aluminum	Lightweight	-100 to +200°C	Lightweight
Stainless steel	Cleaning / Radiation	-100 to +350°C	Corrosion resistance, surface cleanability, nuclear radiation and mechanical resistance
PEI	Sterilization	-65 to +200°C	Sterilization in autoclave, EtO, Cidex, gamma radiation, Steris®, Sterrad®
PBT	Insulation	-65 to +135°C	Electrical insulation, low temperature manipulation
ABS	Cost efficiency	-20 to +65°C	Disposable solutions, medical applications

Contact Block Material

Material Name	Ideal For	Temperature	Main Attributes
PEEK	High temperature	-65 to +250°C	High temperature, high chemical and high radiation resistance
LCP	High temperature	-65 to +200°C	High temperature and high chemical resistance
PBT	Cost efficiency	-65 to +135°C	High chemical resistance, cost efficiency
PTFE	Electrical insulation	-65 to +160°C	High dielectric strength, high chemical resistance
ABS	Cost efficiency	-20 to +65°C	Disposable solutions, good stability

O-Ring & Sealing Material

Material Name	Ideal For	Temperature	Main Attributes
FPM (Viton®)	Hermeticity	-20 to +200°C	Acids, weather, ozone, fuels, mineral and silicone oils, high vacuum, gamma rays
EPDM	Low temperature	-50 to +200°C	Alcohol, weather, hot water, vapour, detergents, gamma rays
NBR	Oil resistance	-30 to +110°C	Acids, mineral oils, petrol, weather, detergents
FVMQ	High temperature oil resistance	-55 to +200°C	Mineral oils, alcohol, weather, hot water, detergents
TPE	Soft accessories	-55 to +130°C	Very resistant, except to aromatic and chlorinated hydrocarbon
Silicone based resin	IP68 sealing	-55 to +200°C	Mineral oils, acids, alkalines, inorganic saline solutions
Epoxy based resin	Hermeticity	-65 to +150°C	High chemical and radiation resistance

Our Series Overview

Five product lines with specific features and benefits for your application requirements and operating environments.



	Highly configurable, the Fischer Core Series offers a great variety of waterproof connectors.	Our ultra-rugged waterproof connectors are compatible with the latest military standards.	Our low profile, 360° mating Freedom connector is cleanable by hand in the water.	Combine water resistance with high-density miniaturization.	A rugged fiber-optic solution designed for outdoor applications.
Number of contacts	1 to 55	2 to 42	4 to 7	4 to 30	1 to 4
Contact termination	Solder \| Crimp \| PCB	Solder \| Crimp \| PCB	Solder \| PCB \| Wires \| ZIF	Solder \| PCB	Optical \| Solder (hybrid)
Locking system	Push-pull \| Quick-release \| Friction	Quick-release \| Push-pull \| Ratchet	Quick-release	Push-pull \| Quick-release \| Screw	Push-pull
Blind mating	✔	✔	✔	✔	✔
Mating cycles	up to 10,000	up to 10,000	up to 1,000	up to 5,000	up to 1,000
Data transfer & power	✔	✔	✔	✔	✔
Contact type	Low voltage \| High voltage \| Coax \| Triax \| Hybrid	Low voltage	Low voltage	Low voltage	Low voltage \| Fiber optic
Sealing level	IP30 to IP69 \| Hermetic	IP68 to IP69 \| Hermetic	IP67 to IP68	IP68	IP67 to IP68
Receptacle sealed unmated	✔	✔	✔	✔	✔
Data protocol compliance	USB 3.2 \| Ethernet \| Single Pair Ethernet \| Audio/UHD Video	USB 3.2 (MP LV or USB-C Interface) \| Ethernet \| Single Pair Ethernet	USB 2.0	USB 3.2 \| Ethernet \| Single Pair Ethernet \| Audio/UHD Video	–
Test voltage DC (kV)	up to 50	up to 3.7	up to 1.2	up to 2.4	up to 2.8
Current rating (A)	up to 60	up to 26	up to 5	up to 10	up to 10
Housing material	Brass \| Stainless steel 316 L \| Aluminum \| PEI (405) \| PBT (4032) \| ABS	Aluminum \| Brass	Metal \| Plastic	Brass	Brass
AWG	9 to 32	9 to 32	24 to 28	18 to 28	17 (hybrid)
Cable outer Ø (mm)	1.5 to 22.7	1.9 to 18.8	5.5	3.0 to 8.7	2.9 to 9.4
Plug size Ø (mm)	9 to 34	12 to 29	20.4 to 25.4	9.9 to 14.9	13 to 24

Discover More About Our Rugged Circular Connectors

Our Original Push-Pull Locking System

Mating
The plug’s outer sleeve, with flexible fingers, slides forwards and backwards along the body.

When Connected
The beveled edges are firmly captured by a locking groove located inside the receptacle.

Pulling the Cable
The beveled edges of the fingers are forced into the groove, securing the connection.

Unmating
Pulling on the outer sleeve of the plug unlocks the latching mechanism.

Other Locking Systems

Lanyard: Combines push-pull automatic locking with an emergency release lanyard.

Quick-release: Designed without a locking mechanism for emergency release.

Friction: Designed without a snapping mechanism.

Tamperproof: Features an integral safety locking ring to prevent unauthorized or unintentional disengagement.

Screw-locking: Enables firm locking by circular movement with the plug’s outer sleeve and receptacle feature threading.

Ratchet: Securely locks mated connectors in place with interlocking teeth.

Extreme Temperature Resistance

Our most rugged series offers standardized products that operate within the temperature range of -55 °C to +135 °C, tested in compliance with the Military Standard 810 Methods 501.6 and 502.6. With the right insulator and cable clam set, Fischer Core connectors can even withstand temperature ranges from -70 °C to +250 °C (and -100 °C upon request).

Vibration and Shock Resistance

Tested in compliance with MIL standard 202 Method 214 and Condition I, our connectivity solutions resist random vibration of up to 37.80 Grms for our most rugged series. Mounted onto vibration equipment, the locking and contact specifications of a circular connector pair are thoroughly verified.

Corrosion Resistance

Protection against corrosion mechanisms – pitting, intergranular or crevice – is achieved by choosing the right materials and type of coating. The most common materials and coatings used are:

Brass with nickel or chromium coating

Stainless steel, which is one of the best materials for corrosion resistance, since corrosion protection is embedded.

Chemical Resistance

In hospital sterile environments, dentistry and laboratory settings, as well as in food and pharmaceutical processing, devices and equipment must be cleaned, disinfected and sterilized on a regular basis. Our products’ components – shells, contact blocks, O-rings and seals, cable jackets, etc. – are made of ultra-resistant materials to withstand the conditions incurred by sterilization methods with chemicals such as Steris LCS, Sterrad and EtO.

Sterilization Proof

If you’re in need of high-performance connectors that withstand most sterilization methods, consider the Fischer Core Series. These circular connectors are made with premium materials making them capable of withstanding temperatures ranging from -70 °C to +250 °C.

Radiation Resistance

Radiation resistance is required for long-lasting tasks in nuclear or contaminated environments such as handling heavy radioactive loads, performing inspections, and repairing equipment – sometimes performed remotely by robot workers due to inaccessibility or the danger of radiation exposure.

Proven and Tested

Off-the-shelf, customized or tailored to your needs, our high-performance solutions are designed to last. In order to reach the highest reliability and quality standards, our circular connectors go through a battery of mechanical and environmental tests, in compliance with industry and military standards such as IEC, EIA, MIL-STD-202 and MIL-STD-810.

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