Shimano’s 12-speed chain
The latest DURA-ACE, ULTEGRA, and 105 road bicycles, as well as the current higher grades of MTB (XTR, DEORE XTR, SLX, and DEORE) use four types of 12-speed-specific chains: CN-M9100, CN-M8100, CN-M7100, and CN-M6100.
CN-M9100 is the highest grade, and the smaller the number up to CN-M6100, the lower the grade of chain.
As for 12-speed chains, MTB chains that have already been converted to 12-speed are also used for road use, and 12-speed chains for road use are not in the product lineup as of August 2022.
Can I use a 12-speed chain from a manufacturer other than Shimano?
KMC’s 12-speed chains
KMC is a standard manufacturer of Shimano-compatible chains in Japan. 12-speed chains include the DLC chain and the popular X chain, both of which are designed for SRAM and Campagnolo and cannot be used with Shimano 12-speed components.
Both will work fine since the KMC site states “Compatibility : SHIMANO, SRAM and all other 12 speed drivetrains”.
In fact, there are reviews on Amazon and other online retailers that say that KMC’s 12-speed chains “worked fine with Shimano 12-speed components,” so it seems like a non-issue.
SRAM and Campa 12-speed chains.
However, as with KMC’s 12-speed chain, it is possible that you will find no problem when you try it, so try it at your own risk.
Because the distance between sprockets is very narrow with 12-speed, shifting compatibility is very severe.
Since all Shimano 12-speed for road use are electric shifting (Di2), it is best to use Shimano stock chains to benefit from the high-speed shifting of Di2, but using KMC chains for color coordination is another fun option.