How Many Types Of M12 Bulkhead Connetor
What Is M12 Bulkhead Connector ?
M12 bulkhead connector is also called M12 panel mount connector, it’s a waterproof connector that mounted on a surface of the device, it has 2 sides, ones side inside the device, and the other side outside of the device, the outside part of the M12 bulkhead connector have M12 interface which could be connected to M12 cable plug, and make the connection waterproof. The internal part of the M12 bulkhead connector have contacts that can be soldered to wires, or PCB type contacts that can be mounted the PCB. The surface of the device should have a hole , the M12 bulkhead connector will be inserted to the hole and locked it by screw, there is O-ring on the connector to make the panel mount waterproof.

The above pictures from Phoenix shows different types M12 bulkhead connector:
① D coded M12 ethernet bulkhead connector (It’s shieled type M12 bulkhead connector which can also be 8 pin X coded )
② M12 SMD bulkhead connector , it’s PCB surface mount connector
③ M12 PCB bulkhead connector , which could be soldered to PCB , the PCB have solder hole for the contact of the connector
④ Front mount M12 Bulkhead connector , mount from front of the device surface , there is also back mount M12 bulkhead connector
How Many Types Of M12 Bulkhead Connetor Are There ?
Sorted by different mothod there’re many different types of M12 bulkhead connector:

Sort by Coding type :
- M12 A coded bulkhead connector have 2 pin , 3 pin , 4 pin , 5 pin , 6 pin , 8 pin , 12 pin , 17 pin for option, could be back mount, front mount , PCB mount (straight or right angle), SMD type , the A coded M12 bulkhead connector mainly used to connect sensor and actuator cables .
- M12 B coded bulkhead connector have 4 pin and 5 pin , mainly used for fieldbus , such as to connect Interbus cables and Profibus cables .
- M12 C coded bulkhead connector have 3 pin , 4 pin , 5 pin , 6 pin , have front or back mount , PCB mount
- M12 D coded bulkhead connector only have 4 pin , which had been widely used for ethernet , so it’s also called M12 ethernet bulkhead connector , have front mount , back mount , PCB mount , SMD type
- M12 X coded bulkhead connector only have 8 pin , it’s also been called M12 ethernet bulkhead connector , can provide much faster data transmission, can be front mount , back mount , PCB mount , SMD type .
- M12 S coded bulkhead connector have 2 pin , 3 pin (2+PE) , 4 pin (3+PE) , front mount type , back mount type , PCB mount type , could be used for AC power connection , have rated voltage up to 630V, rated current 16A
- M12 T coded bulkhead connector have 2 pin , 3 pin (2+PE) , 4 pin (3+PE) , mainly used to power DC devices, supply rated voltage 60V, and rated current 12A , more customer choose it to replace the M12 A coded bulkhead connector for DC power supply , have installation types as front mount , back mount and PCB mount.
- M12 K coded bulkhead connector have 2 pin , 3 pin (2+PE) , 4 pin (3+PE), 5 pin (4+PE) , could supply rated voltage 800V, rated current 16A, transmit total power 12KW, realizes high power transmission at the compact interface , it can be front mount , back mount , PCB mount .
- M12 L coded bulkhead connector have 2 pin , 3 pin (2+PE) , 4 pin (3+PE) , 5 pin (4+PE) , installation solution as front and back mount , PCB mount , used a lot for PROFINET DC power applications .
- M12 M coded bulkhead connector 2 pin , 3 pin (2+PE) , 4 pin (3+PE) , 5 pin (4+PE) , 6 pin (5+PE) , had been used a lot for three phase AC power supply connection , supply rated voltage AC630V and rated current 8A , have installation solutions as front and back mount , PCB mount .

Sort by application
As the M12 bulkhead connector is used for M12 waterproof plug connection in automation field , such as industrial ethernet , industrial sensor , actuator , I/O modules , control carbinets, and other devices that need waterproof data and power connection .
Industrial ethernet : M12 ethernet bulkhead connector , M12 to RJ45 bulkhead connector

As we talked in the coding type , M12 D coded bulkhead and M12 X coded bulkhead are mostly used for M12 ethernet bulkhead connector . D coded M12 4 pin bulkhead connector only use 4 contacts , the data transmission speed is 100Mbps , and X coded M12 8 pin bulkhead connector have 8 contacts , data transmission speed could reach 10Gbps , both D and X coded M12 ethernet bulkhead connector could be made M12 to RJ45 bulkhead .
The M12 to RJ45 bulkhead is mostly back mount , with metal shielding tube to make the contact and cable connection shielded , it’s normally used inside the device, as the contact and cable connection is not waterproof. It’s one side with M12 X coded or D coded bulkhead connector , the other side is RJ45 connector , it’s prewired M12 bulkhead connector , the cable length could be customized . The M12 to RJ45 bulkhead cable have PVC and PUR material for option , as the cable is normally used inside the device , the work environment would not be very bad.
The 2nd and 4th M12 ethernet bulkhead connector is PCB type, first soldered to the PCB, and then installed to the bulkhead. It’s important to have right PCB drawing and solder hole to install the right angle M12 ethernet bulkhead connector.
Sensor Actuator M12 Bulkhead Connector
As we know, some of the M12 cables is also called M12 sensor cable, M12 actuator cable, as they’re used to connect the sensor and actuator, so most industrial sensors have M12 bulkhead connector installed.

Not all the sensors will need M12 bulkhead connector, some of the sensor just use cable glands, and some of them may just moulded the cable in the sensor.
For sensor and actuator application, M12 3 pin bulkhead connector , M12 4 pin bulkhead connector , M12 5 pin bulkhead connector are the mostly used. And the male M12 bulkhead connector is more popular on senors.
M12 Bulkhead Connector Sort By Installation Method
As mentioned in the above content, the M12 bulkhead connector could be installed front of the bulkhead , back of the bulkhead, all will need installation hole on the bulkhead, customer will choose depends actual application requirment.
Front mount M12 bulkhead is also front M12 panel mount connenctor
It’s mounted in front of the bulkhead but srewed back of the bulkhead, it can be male or female , all the A code B code C code D code X code Y code S code T code K code L code and M code different coding type have front mount M12 bulkhead, and all the pin options 2 pin , 3 pin , 4 pin , 5 pin , 6 pin , 7 pin , 8 pin , 12 pin , 17 pin can be front mount.
It has 2 different size locking threads, M12 and PG9, some customer may need it M20 thread, it can be customized.

The above picture shows male and female M12 bulkhead connector with M12 thread and PG9 thread. The bulkhead M12 connector with M12 thread have a installation hole of OD 12.1mm circle, when it’s installed, while mating with the M12 plug, the M12 bulkhead connector front mount may rotate, then the wires inside the device may have risk of twisted together, sometimes the wires may be disconnected or shorted.
But for the M12 bulkhead connector with PG9 thread (M16X1.5mm), after it installed, as the install hone is not a standard circle, it couldn’t rotate, so it’s more safe and reliable, and customers choose the PG9 thread ones more for their application.
Back mount M12 bulkhead is also called back M12 panel mount connenctor
Different as front M12 panel mount connector, back mount M12 bulkhead connector is installed back of the bulkhead, and screw locked front of the bulkhead,same as front mount M12 bulkhead, it also have M12 and PG9 locking thread for option(the female bulkhead M12 connector only have PG9 thread for option).

M12 Bulkhead Connector Sort By Contact Termination
The bulkhead M12 connector could be solder type, PCB type, SMD type if sort by contact termination, the above front mount and back mount M12 bulkhead connector are solder types, can be soldered with wires or not soldered before leave manufacturer(the wire length could be customized), users can soldered the wires them themselves.

M12 PCB Bulkhead Connector

M12 PCB bulkhead connector is also called M12 PCB connector , M12 PCB mount connector , as the connctor need to soldered to PCB, if it’s front mount, ask soldered to PCB, it would be hard to install, so most M12 PCB bulkhead connectr is back mount. The M12 PCB mount connector have A coded 2 pin 3 pin 4 pin 5 pin 6 pin 8 pin 12 pin 17 pin , B coded 4 pin 5 pin , C coded 3 pin 4 pin 5 pin 6 pin , D coded 4 pin , and S coded , T coded , K coded , L coded , M coded.
A coded, D coded , C coded, D coded, X coded, Y coded all the pin types have straight and right angle M12 PCB connector , S coded T coded K coded L coded M coded only have straight type PCB M12 connector.
M12 SMD Bulkhead Connector
M12 SMD bulkhead connector is also called M12 SMD connector, M12 SMD mount connector, it can be front mount or back mount, the insulator could be surface mounted to the PCB, and then install the shell in front or back of the bulkhead.

The SMD M12 bulkhead connector only have A Coded , B coded , and D coded , A coded 2 pin , 3 pin , 4 pin , 5 pin , 6 pin , 8 pin , 12 pin , 17 pin all available.
Square M12 Bulkhead Connector
All the above connectors have a circular shape, there is also square M12 bulkhead connector, they need 5 holes for installation, 4 of them for locking screws, and the big one for solder wiring.

The hole position and hole size is very important to install the square M12 bulkhead connector, you may get this drawing from manufacturer.
These information may help you understand M12 bulkhead connector , if you have any questions we can help, welcome to contact us.
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