Chain splitters. Recommend a strong one

This one from park is great, super stiff, and it comes in a specific 1/8" size (CT-7 i think, also fits massive 3/16" chains). I use it in the workshop nearly every day and i've had it for fookin ages!

I bust one of these yesterday.

Spare pins available, but not so tough.

At least they take hefty chains.