Part numbering explained

If you already know most or all of your part number and would like to obtain more detailed information click on the link below.

LEMO Part Search

If you have not yet selected a connector then click on the link below for another option whereby you can select by market segment, number and types of contacts, cable diameter etc.

LEMO Product Finder

The modular design of LEMO connectors is such that there is potentially a huge number of options available. In order to manage this the part numbering system is descriptive and reflects this modular design. Although there are varations between connector series, the table below gives an indication of the structure, which will help you in understanding your connector.

LEMO part number general structure:

Part number structure1


Secure connection

Most applications rely on a secure method of connection that is not only reliable but also quick to use.

The LEMO self-latching system is designed to offer the user the ability to mate the connectors quickly and with ease of operation, ideal when blind mating is required. 

The system provides security against vibration, shock or pull on the cable. 

LMEO Push Pull connectors


Precision contact

LEMO Contact Materials
The unique design of LEMO’s contacts provide for a secure, reliable connection in any environment.
Contact Materials
All contacts, male and female, are machined from solid before being plated with nickel and then gold. The female contacts are designed to eliminate misalignment during mating and to ensure that, when mated, a constant even force is maintained on the male contact.These features provide for a long operational use by combining an extremely high level of mechanical reliability with low electrical resistance.
Electrical Contact
The secure reliable electromechanical connection achieved with LEMO female cylindrical contacts is mainly due to two important design features :
LEMO precision contacts
Precision contacts
1. Prod proof entry on the mating side which ensures perfect concentric mating even with carelessly handled connectors.

2. The pressure spring, with good elasticity, maintains a constant even force on the male contact when mated. The leading edge of the pressure spring preserves the surface treatment (gold-plated) and prevents undue wear.

Modular construction

The modular construction of the LEMO range of connectors allows the user to choose the right configuration for their ideal connector to suit the application.LEMO modular construction

The ability to select from the wide range of housings and contact types (including coaxial, triaxial, multipole, unipole, high voltage, fibre optic and hybrids versions) provides the user with an enormous range of potential options from which to make a selection. 

Example of Modular Construction

Modular construction


Wide range of shells and contacts

LEMO offer many thousands of configuration options when selecting your connectors. Within the LEMO range the user is able to choose the shell style of both plug and socket to suit the individual application

Plugs: Straight, Elbow and Fixed Shell Styles. Options include lanyard and remote handling options
Sockets: Fixed (Front or Back Panel Mounting), Free and Coupler Shell Styles
Unipole: Crimp, Solder, PCB straight & elbow

Both plugs and sockets can be supplied in a variety of base materials including brass, stainless steel or Avional along with a choice of finishes to suit the application. Additional to the shell options are the contact types which may be chosen to suit the application.

Multipole: Crimp, Solder, PCB straight & elbow
High Voltage
Fibre Optic

LEMO are also able to offer hybrid connectors, which encompass the contact types above.

Space Savings

The design of the LEMO range of connectors allows for considerable space savings to be made by the user.

M vs MIL 7

The use of hybrid configurations allows for contact types to be combined into one shell configuration eliminating the need for multiple plugs to be used.
The design of latching mechanism allows for the distance between connectors on a panel to be reduced to a minimum amount. This can provide substantial panel savings compared to traditional MIL Spec connectors.
In addition, LEMO are able to offer reductions with PCB contact lengths in comparison to Mil Spec connectors thus allowing the user to reduce the depth of their enclosures in some applications.

High Reliability

Two important areas within the design of the connectors which can effect reliability are the ability to maintain the secure latching mechanism and the contact resistance performance over the product lifetime, typically 5000 cycles.

The latching mechanism has been design to ensure that maximum retention force is achieved whilst the connector is mated, to prevent accidental release, whilst requiring only minimal force to mate and de-mate the connector under normal use.

The design and manufacture of the contacts ensures that there is a minimal effect on the contact resistance caused through wear.


EMC Properties

When selecting a connector, shielding efficiency and excellent electrical continuity between connector and cable may be important features to consider

EMC Compatibility chart

as part of the selection process.

The design of LEMO connectors, with metal shell and earthing crown, provides for 360 screening. Full screening guarantees optimum shielding efficiency in all applications where electromagnetic compatibility (EMC) is critical.

Fast Connector Modification

On occasion, customers will require a configuration which LEMO does not have as a current manufactured item. Quick  Modification to suit Application

Due to the modular design of the range, it is an easy process to make modifications to shells, contacts or both to meet the customer specification.

This process can be applied to both metal or plastic housings with minimal delay. Additionally, the insulator can be adapted to suit most contact configurations if required.

All development work is carried out by LEMO in accordance with the customer specification. This includes full CAD design, any new or modified tooling required and samples.

The ability for LEMO to utilise many existing parts reduces the need for all parts to be modified or new connector designs to be undertaken which can dramatically reduce project leadtimes.