In steelworker parlance, a cobble is a bit of steel that catches on a roller during manufacturing.
Cobbles cause the molten steel coming out of the furnace to back up and snake wildly around.
This guy was lucky to be uninjured after a close call with a cobble.
Here’s a short explainer:
Another spectacular cobble:
And another cobble:
• Bar mill cobble (YouTube / Azhar Hussain via Digg)