New here to Shimano chains and 12 speed. Always used KMC 10speed chains with reusable quick links included. New bicycle was delivered with RD B screw way out of spec and resulted in me having to cut the chain. This means I had to open the Shimano SM-CN910 12 speed quick link, cut 2 links out and reinstall the quick link. Then, DOH, accidentally installed the quick link with arrows facing the wrong direction. In effect, I reinstalled the quick link twice.

So, Shimano states, do not reuse their quick links. Does my usage without ever having ridden the bicycle constitute reuse? It certainly took the Park tool to separate the link and again to install it with a very solid click.

Take them apart and put them back together 15 to 20 times before discarding, with no negative consequences. The one use specification is probably authored by liability attorneys on retainer.

I heard on this forum that many consider "one use" to mean the life of the chain. Sounds good to me.

If they don't snap shut, I replace them.

Barry

I buy quick links in packs of three, but find that I never need the additional links unless I manage to lose one during chain cleaning.

Might one enquire why you bothered buying a second pack? 😄

I use them over and over without a problem

Corporate is going to error on the side of caution.
I've not had issues reusing the 12 speed QL.

I find installing the KMC 12 spd. easier. The Shimano version gives me trouble closing, even when using the tool.

You don’t use a tool to close it?

At least, I never have.

Just to clear this up, what they "really" mean is to not use the quick link on the NEXT chain. People who clean their chains off the bike or use wax are removing their chains every few hundred miles are re-using their quick links many times. But the quick link wears with the chain, so when the chain is worn out, so is the quick link.