Definition
when a situation reaches a critical point, requiring a firm decision or action.
到了关键时刻
If it comes to the crunch, we may need to cut our budget.
如果情况变得严峻，我们可能需要削减预算。
When it comes to the crunch, you see who you can really depend on.
当情势发展到关键时刻，你就能看出谁是真正可以依靠的。
Though he was hesitant at first, when it came to the crunch, he decided to support us.
虽然他起初犹豫不决，但当情势发展到关键时刻，他决定支持我们。