LEMO connector

I am trying to work out what sort of LEMO socket to buy. All I know is it 6 pin with a single key, in one of the smaller sizes, and that the diameter of the plug shaft is approx 9.5mm. I have routed cabling up to the headset connection area to power LEMO style headsets so these can be used instead of the regular GA connectors

Real fucking rabbit-hole.

Can buy a LEMO socket from (looks plasticy, but cheap)

Pilot Communications 6 Pin Lemo Panel Mount Jack (Bose/Lightspeed Headsets)

Pre-wired from (expensive!)

LEMO chassis socket (wired) - from Mendelssohns

Bose 6 Pin Lemo Headset Install Connector Kit | Aircraft Spruce Australia

LEMO selection guides

Solutions_Selection_Guide_web.pdf

Interested in indoor keyed, B or S, not sure of size

Not sure what a stepped insert is.

AI:

What is a LEMO stepped insert?

LEMO stepped insert

The stepped insert in LEMO connectors is a design feature that facilitates proper alignment for the connectors. This design is particularly useful in the E Series Connectors, which are known for their ergonomic self-latching Push-Pull system. The stepped inserts allow for easy alignment and blind mating, making it simpler to connect the connectors without the need for precise alignment. This feature is especially beneficial in demanding and harsh environments where the connectors may be subjected to various conditions. 

Are LEMO stepped insert compatible with normal insert:

Not compatible with normal inserts

LEMO stepped inserts are not compatible with normal inserts. They are designed specifically for the stepped insert system, which provides easy alignment and blind mating. The stepped inserts are part of the E Series connectors, which are known for their rugged housing and compatibility with S-series inserts in many configurations. This compatibility ensures that stepped inserts can be used with other stepped inserts, providing a seamless connection in various applications.

Also

Are LEMO B series compatible with Redel?

Yes

Note 27 Mar 2026 - WRONG!!!! The pins and central core match but the locking collar have totally different dimensions

Yes, LEMO B series connectors are compatible with REDEL connectors. The REDEL® plastic push-pull connectors are manufactured by LEMO® under the REDEL® name, indicating that they share the same reliable contact system and many of the same insert configurations as LEMO’s B series connectors.

So use B series only

https://media.digikey.com/PDF/Data%20Sheets/Lemo%20PDFs/S&B_Series_Catalog.pdf

The shaft of the Bose LEMO was measured to be 9.5mm approx. So dimension A must exceed this by some margin. This rules out the 0B series. This leaves only the 1B series. This is consistent with the REDEL connector only being in available P1

So a candidate connector is EGG-1B-306-CLL

1B size

https://au.element14.com/lemo/egg-1b-306-cll/socket-panel-mount-1b-6way/dp/3817155 - in stock AUD$57.89

Data sheet: Unipole Multipole catalog

REDEL P_series - Redel connectors

Interested in the push-pull series. I have seen reference to Redel P1 in relation to some headsets

I note the series starts at P1, the following are relevant

Requires a 14mm hole

Clearly M0.6 is relevant

Clearly G key and L contact type are relevant

A black outershell and grey front nut is a good match for the black LEMO plug on Bose headsets

A suitable fixed socket is

PKG.M0.6+suffix

or

PKG.M0.6+suffix

Mouser

NL.LN black outershell (PSU), black front nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6NL.LN?qs=BpQ5zMcxL3C1uTdHEcr5CA%3D%3D non stocked

SL.LG grey outershell (PEI), grey front nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6SL.LG?qs=GJUnMDfnT2yA7nMP%252BM98xQ%3D%3D in stock

Prefer this one - $41.23

Data sheet: PKG.M0.6SL.LG.PDF

SL.LN grey outershell (PEI), black front nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6SL.LN?qs=FtUJHUU4yUk4IVwF4YOPRw%3D%3D in stock

TL.LG black outershell (PEI), grey front nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6TL.LG?qs=mDYDupiwM4BPLshSw7SSIQ%3D%3D non stocked

TL.LN black outershell (PEI), black front nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6TL.LN?qs=mDYDupiwM4DvYW2o4ymyAQ%3D%3D non stocked

PEI is good to 170C, PSU to 150C

black outershell, grey front nut (NL.LG) is missing from mouser range

Given the panel on which the LEMO is mounted can be removed, maybe a single nut solution is ok

PLG instead of PKG

PLG.M0.6+suffix

GL.LG grey outershell, grey fixed nut

https://au.mouser.com/ProductDetail/LEMO-REDEL/PLG.M0.6GL.LG?qs=nwALWJny2wWtph7lPKUtQw%3D%3D no stock

NL.LN black outershell, black fixed nut

https://au.mouser.com/ProductDetail/LEMO/PLG.M0.6NL.LN?qs=FmjOKN4Os864LJFUNJ275g%3D%3D non stocked

But access to tighten the rear nut could be a problem owing to the enclosure shape

Summary

Are LEMO 1B series compatible with Redel P1?

AI: Compatible

Note 27 Mar 2026 - WRONG!!!! The pins and central core match but the locking collar have totally different dimensions

The LEMO 1B series connectors are compatible with the REDEL P1 series connectors. Both series offer high-quality, sterilizable connectors designed for medical applications, ensuring reliable connections in various environments.

EGG: front diameter 14mm, nut diameter 16mm, hole 12mm, maximum depth 23mm

https://au.element14.com/lemo/egg-1b-306-cll/socket-panel-mount-1b-6way/dp/3817155

I ordered these, they are NOT compatible with the LEMO connectors associated with headsets

Matching dust cover

BRA.1B.200.PCSG LEMO | Connectors, Interconnects | DigiKey 0 in stock

BRA.1B.200.PCSG LEMO | Mouser Australia 37 in stock

PKG: front diameter 19.2mm, nut diameter 19.2mm, hole 14mm, maximum depth 23mm

https://au.mouser.com/ProductDetail/LEMO-REDEL/PKG.M0.6SL.LG?qs=GJUnMDfnT2yA7nMP%252BM98xQ%3D%3D

The EGG is clearly more compact, so preferred - DOES NOT FIT

This might be a better bet:

Photos provided by retailer

29 March 2026:

It is most probable that the cap above will not fit the Redel type socket, given it designation1B. So there is no cap for the Redel type socket. The lack of a cover is problematic given these sockets will not be mounted vertical but will face up so are liable to collect dust and debris over time. The connections exposed by these sockets are shared with the GA connector mic and headphone signals, and a power bus. I have decided to dump the idea of adding LEMO support for the time being, but will consider laying in the single power wire.