Strike while the iron is hot
Blacksmithing origin explains real metalworking principle
Act quickly while the opportunity is still available. Blacksmiths working iron by hand heat the iron in a fire to red-hot making it malleable. The Smith removes the iron from the fire and shapes it with blows from a hammer. They need to work quickly before the iron cools. Once the iron is cool, it becomes brittle and the opportunity to hammer it into shape has passed.
If you want the job, you need to strike while the iron is hot.
Also in the dictionary
- strike while the iron is hot in metallurgy