What Are DIN 43650 Plugs?

Post By: Tom Rowse On: 14-12-2023 Read Time: 5 minutes - Guides - Pneumatics

DIN 43650 plugs are a range of solenoid valve connectors used in many industrial applications. They are now known under the standard EN 175301-803. They’re sometimes also referred to as ISO 4400 connectors, under a standard for electrical connectors drawn up by the International Organisation for Standardisation. The original title refers to the German standard-setting organisation, Deutsches Institut fur Normung (DIN). DIN 43650 connectors are also sometimes called MPM or sugarcube connectors. 

Electrical connectors are designed as a reliable and rapid interface for connecting and disconnecting electrically driven industrial components. These include pneumatic and hydraulic valves, motor drives and pressure switches. User-friendly assembly and innovative methods of wire connection allow for easy installation of EN 175301-803 plugs to an electrical device. The plugs or solenoid valve connectors are offered in many circuit versions, to meet all sorts of specific application requirements.

Types Of DIN 43650 Connectors

DIN 43650 solenoid valve connectors are manufactured in three separate formats, called Form A, B or C. They’re categorised according to various over-voltage protection requirements and each functions within defined voltage limits. Each form is comprised of basic characteristics including: 

  • pin type

  • pin count

  • pin spacing

  • cable entry type 

  • housing type

  • gasket type

  • thread

  • base shape


The measurement for pin spacing is different for each form It always represents the distance between pins #1 and #2. Pin types also vary according to the form:

  • Form A connectors have an 18 mm pin spacing, with “U” shape pins facing inwards.

  • Form B connectors have either 10mm or 11mm pin spacing: 10mm connectors have two U-shape pins facing outward, plus one flat blade;  industry-standard 11mm connectors have three flat blade contacts

  • Form C connectors have either 8mm or 9.4mm (industry standard) pin spacing with flat blades 

What Are DIN 43650 Plugs

Thread Types

DIN 43650 plugs also feature different thread types for the cable entry, according to the form: 

  • Form A connectors currently come in 1/2” NPT, PG 9, PG 11 or M16 thread sizes Form B connectors are only available in 1/2” NPT or PG 9 threads

  • Form C connectors only come with PG 7 thread 

  • NPT (National Pipe Thread) is a US standard which has tapered threads, unlike metric or PG. Tapered threads make it easier to form a seal. 

  • PG (Panzergewinde) is a German standard with larger thread angles, It has a lower thread depth than either NPT or metric. 

  • M16 is a metric thread type, and the one most commonly used worldwide. The number stands for the nominal diameter of the thread measured in millimetres. 


DIN 43650 plugs are available in three gasket options made of synthetic copolymer rubbers called ethylene-propylene-diene-monomer (EDPM) or nitrile butadiene (NBR). The three options are NBR Flat, NBR Profile or EPDM Flat. 

  • Each type of gasket has different characteristics, mainly due to the material of manufacture. 

  • NBR or nitrile rubber is resistant to both vegetable and mineral oils. 

  • EPDM rubber isn’t very resistant to oils, but performs well against threats like heat, weather and ozone. 

  • Both materials hold up well against basic diluted acids and alkalines. 

Other Differences 

Other variables for Forms A, B and C include: 

  • contact resistance and spacing 

  • cable dimensions

  • type of termination

  • maximum conductor size

  • nominal current

  • operating temperature

  • protection class 

  • availability of UL listing

Each form also has distinct characteristics which distinguish it from the other two, such as manufacturer’s place of origin, and the materials and dimensions of its housing, base, centre screw and contacts. 

Additional Connector Options

DIN 43650 plugs can be customised with several additional options, often supplied as  Form A special circuits:

  • Bridge rectifiers that convert AC input into DC output 

  • LED indicators that confirm the voltage supply

  • Switching amplifiers that control the output

  • Resistor-capacitors (RC) that take in power surges and discharge them

  • MOV suppression to provide the source and load with over-voltage protection 

  • Diodes that redirect a surge to provide over-voltage protection 

  • Z or Zener Diodes that also redirect surges, and in the case of over-voltage also block off a circuit

  • Moulded cable, in various lengths, with PUR or PVC jacket

What Are DIN 43650 Connectors Used For?

Solenoid connectors are an essential component in many devices and systems, including specialised equipment, machinery and control systems. They’re designed to provide a reliable and secure connection between the valve and the device or system it’s connected to. This enables the flow of air, electricity or other media through the connector to the valve. 

DIN 43650 plugs/EN 175301-803 connectors are most often used in conjunction with hydraulic, pneumatic and electromagnetic devices. These include solenoid valves. You’ll also find them in proximity switches, limit switches, level sensors, pressure transducers and low-energy motors. They can be modified to build in surge suppression, indicator lights and moulded cable, but in are generally not affected by electromagnetic interference or voltage surges.

Form A connectors are intended for use with solenoid valves in pneumatic or hydraulic applications, as they offer a water-resistant method for supplying power securely.

Form B connectors are also sometimes called micro connectors. Like Form A, you’ll find them used on solenoid valves in pneumatic and hydraulic equipment, and also in various marine applications.

Form C connectors come in even smaller sizes than Form B, and are often referred to as sub-micro connectors. You’ll find them in the same solenoid valve environments as Forms A and B, providing a secure, water-resistant means of supplying power. As well as marine applications, you’ll also find them in pressure sensors and switches, proximity switches, optical and limit switches.

Convenient Choice

DIN 43650/EN 175301-803 connectors have cornered much of the market in the large-scale electronics industry. They’re found in many electrical devices in most other industrial sectors too, primarily in use on solenoid valves and various types of electronic switch.

Their widespread popularity is due to their plug-and-play ability, straight out of the box. They’re quick to assemble and operate, reducing any work required for installation and its associated labour costs. The variety of forms and optional configuration of specialised components make the DIN 43650 connector a highly convenient choice.