The keys to steel mills at Dalzell and Clydebridge in Scotland have been formally handed to new owners, heralding "a new era" for the factories which had been threatened with closure.
Scottish First Minister Nicola Sturgeon hailed international metal firm Liberty House's takeover from Tata Steel as a demonstration of the "art of the possible" at the handover ceremony in Motherwell, North Lanarkshire.
The plants were secured last month in a "back-to-back" agreement, involving the Scottish Government buying them from Tata Steel, and immediately selling them on to Liberty.
Ms Sturgeon offered to advise the UK and Welsh governments on its experience to prevent the closure of another Tata plant at Port Talbot in Wales.
She told Sky News: "This is the art of the possible.
"I am standing here as First Minister in the happy position of saying that we're about to hand over two steel plants that otherwise would have closed to a new owner that wants to get them back into operation, employing people and producing steel.
"I very much hope that in the not-too-distant future that the UK Government and Welsh Government might be able to say the same about Port Talbot.
"Any experience that we have got here that we can bring to bear we will be very happy to do so."
Ms Sturgeon the sale "is the beginning not just of a new era for Scottish steel, but a new era that builds on the huge experience and high skillset of the workforce at Dalzell and Clydebridge".
Liberty House expects to create 150 jobs to get the plants up and running again.
Scottish business minister Fergus Ewing said: "When we convened the Scottish steel taskforce back in October, we did so with a determination to do everything possible to secure a new operator and to do whatever we could to make the plants an attractive proposition.
"Over the course of eight taskforce meetings and a lot of other engagement we made significant progress in five key areas to support the industry, namely business rates, energy costs, environmental issues, skills and procurement.
"It has been a team effort which has paid off and once again the steelworkers of Scotland will produce world-class products from here in Lanarkshire."
The sale process for Port Talbot is due to start on Monday and steelworkers await a buyer stepping forward to secure their jobs.
Workers at the plant said on Thursday they were ''encouraged'' about efforts to save their jobs after hearing from the UK Business Secretary that Tata is planning to act responsibly over the sale of its UK assets.
Sajid Javid flew back from a meeting in Mumbai - at which he pressed Tata officials for more time over the sale of its steel plants - to spend hours at Port Talbot in talks with unions and staff.
He cut short the trip to visit Port Talbot amid union claims he had "taken his eye off the ball" as the UK steel industry crisis deepens.
Mr Javid had been in Australia on a business trip when the steel firm made the announcement it was selling its loss-making plants just over a week ago.